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Hindawi Publishing Corporation
Discrete Dynamics in Nature and Society
Volume 2010, Article ID 349158, 14 pages
doi:10.1155/2010/349158




Research Article
A Hybrid Method for a Countable Family of
Multivalued Maps, Equilibrium Problems, and
Variational Inequality Problems


        Watcharaporn Cholamjiak1, 2 and Suthep Suantai1, 2
        1
            Department of Mathematics, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
        2
            PERDO National Centre of Excellence in Mathematics, Faculty of Science, Mahidol University,
            Bangkok 10400, Thailand

        Correspondence should be addressed to Suthep Suantai, scmti005@chiangmai.ac.th

        Received 26 January 2010; Accepted 21 April 2010

        Academic Editor: Binggen Zhang

        Copyright q 2010 W. Cholamjiak and S. Suantai. This is an open access article distributed under
        the Creative Commons Attribution License, which permits unrestricted use, distribution, and
        reproduction in any medium, provided the original work is properly cited.

        We introduce a new monotone hybrid iterative scheme for finding a common element of the set of
        common fixed points of a countable family of nonexpansive multivalued maps, the set of solutions
        of variational inequality problem, and the set of the solutions of the equilibrium problem in a
        Hilbert space. Strong convergence theorems of the purposed iteration are established.




1. Introduction
Let D be a nonempty convex subset of a Banach spaces E. Let F be a bifunction from D × D
to R, where R is the set of all real numbers. The equilibrium problem for F is to find x ∈ D
such that F x, y ≥ 0 for all y ∈ D. The set of such solutions is denoted by EP F . The set D
is called proximal if for each x ∈ E, there exists an element y ∈ D such that x − y d x, D ,
where d x, D        inf{ x − z : z ∈ D}. Let CB D , K D , and P D denote the families
of nonempty closed bounded subsets, nonempty compact subsets, and nonempty proximal
bounded subsets of D, respectively. The Hausdorff metric on CB D is defined by


                                H A, B      max sup d x, B , sup d y, A                                   1.1
                                                    x∈A           y∈B



for A, B ∈ CB D . A single-valued map T : D → D is called nonexpansive if T x−T y ≤ x−y
for all x, y ∈ D. A multivalued map T : D → CB D is said to be nonexpansive if H T x, T y ≤
2                                                     Discrete Dynamics in Nature and Society

 x − y for all x, y ∈ D. An element p ∈ D is called a fixed point of T : D → D resp.,
T : D → CB D if p T p resp., p ∈ T p . The set of fixed points of T is denoted by F T . The
mapping T : D → CB D is called quasi-nonexpansive 1 if F T / ∅ and H T x, T p ≤ x − p
for all x ∈ D and all p ∈ F T . It is clear that every nonexpansive multivalued map T with
F T / ∅ is quasi-nonexpansive. But there exist quasi-nonexpansive mappings that are not
nonexpansive; see 2 .
        The mapping T : D → CB D is called hemicompact if, for any sequence {xn } in D
such that d xn , T xn → 0 as n → ∞, there exists a subsequence {xnk } of {xn } such that
xnk → p ∈ D. We note that if D is compact, then every multivalued mapping T : D → CB D
is hemicompact.
        A mapping T : D → CB D is said to satisfy Condition (I) if there is a nondecreasing
function f : 0, ∞ → 0, ∞ with f 0          0, f r > 0 for r ∈ 0, ∞ such that


                                     d x, T x ≥ f d x, F T                               1.2


for all x ∈ D.
        In 1953, Mann 3 introduced the following iterative procedure to approximate a fixed
point of a nonexpansive mapping T in a Hilbert space H:


                            xn   1   αn xn   1 − αn T xn ,   ∀n ∈ N,                     1.3


where the initial point x0 is taken in C arbitrarily and {αn } is a sequence in 0, 1 .
       However, we note that Mann’s iteration process 1.3 has only weak convergence, in
general; for instance, see 4–6 .
       In 2003, Nakajo and Takahashi 7 introduced the method which is the so-called CQ
method to modify the process 1.3 so that strong convergence is guaranteed. They also
proved a strong convergence theorem for a nonexpansive mapping in a Hilbert space.
       Recently, Tada and Takahashi 8 proposed a new iteration for finding a common
element of the set of solutions of an equilibrium problem and the set of fixed points of a
nonexpansive mapping T in a Hilbert space H.
       In 2005, Sastry and Babu 9 proved that the Mann and Ishikawa iteration schemes
for multivalued map T with a fixed point p converge to a fixed point q of T under certain
conditions. They also claimed that the fixed point q may be different from p. More precisely,
they proved the following result for nonexpansive multivalued map with compact domain.
       In 2007, Panyanak 10 extended the above result of Sastry and Babu 9 to uniformly
convex Banach spaces but the domain of T remains compact.
       Later, Song and Wang 11 noted that there was a gap in the proofs of Theorem 3.1
 10 and Theorem 5 9 . They further solved/revised the gap and also gave the affirmative
answer to Panyanak 10 question using the following Ishikawa iteration scheme. In the main
results, domain of T is still compact, which is a strong condition see 11, Theorem 1 and T
satisfies condition I see 11, Theorem 1 .
       In 2009, Shahzad and Zegeye 2 extended and improved the results of Panyanak 10 ,
Sastry and Babu 9 , and Song and Wang 11 to quasi-nonexpansive multivalued maps.
They also relaxed compactness of the domain of T and constructed an iteration scheme which
removes the restriction of T , namely, T p     {p} for any p ∈ F T . The results provided an
affirmative answer to Panyanak 10 question in a more general setting. In the main results,
Discrete Dynamics in Nature and Society                                                      3

T satisfies Condition I see 2, Theorem 2.3 and T is hemicompact and continuous see 2,
Theorem 2.5 .
       A mapping A : D → H is called α-inverse-strongly monotone 12 if there exists a
positive real number α such that


                        Ax − Ay, x − y ≥ α Ax − Ay 2 ,         ∀x, y ∈ D.                  1.4


Remark 1.1. It is easy to see that if A : D → H is α-inverse-strongly monotone, then it is a
 1/α -Lipschitzian mapping.
      Let A : D → H be a mapping. The classical variational inequality problem is to find a
u ∈ D such that


                                   Au, v − u ≥ 0,    ∀v ∈ D.                               1.5


The set of solutions of variational inequality 3.9 is denoted by V I D, A .

Question. How can we construct an iteration process for finding a common element of the
set of solutions of an equilibrium problem, the set of solutions of a variational inequality
problem, and the set of common fixed points of nonexpansive multivalued maps ?

        In the recent years, the problem of finding a common element of the set of solutions
of equilibrium problems and the set of fixed points of single-valued nonexpansive mappings
in the framework of Hilbert spaces and Banach spaces has been intensively studied by many
authors; for instance, see 8, 13–20 and the references cited theorems.
        In this paper, we introduce a monotone hybrid iterative scheme for finding a common
element of the set of a common fixed points of a countable family of nonexpansive
multivalued maps, the set of variational inequality, and the set of solutions of an equilibrium
problem in a Hilbert space.


2. Preliminaries
The following lemmas give some characterizations and a useful property of the metric
projection PD in a Hilbert space.
       Let H be a real Hilbert space with inner product ·, · and norm · . Let D be a closed
and convex subset of H. For every point x ∈ H, there exists a unique nearest point in D,
denoted by PD x, such that


                                x − PD x ≤ x − y ,     ∀y ∈ D.                             2.1


PD is called the metric projection of H onto D. We know that PD is a nonexpansive mapping of
H onto D.
4                                                                    Discrete Dynamics in Nature and Society

Lemma 2.1 see 21 . Let D be a closed and convex subset of a real Hilbert space H and let PD
be the metric projection from H onto D. Given x ∈ H and z ∈ D, then z PD x if and only if the
following holds:

                                              x − z, y − z ≤ 0,       ∀y ∈ D.                                 2.2


Lemma 2.2 see 7 . Let D be a nonempty, closed and convex subset of a real Hilbert space H and
PD : H → D the metric projection from H onto D. Then the following inequality holds:

                        y − PD x    2
                                             x − PD x   2
                                                            ≤ x − y 2,     ∀x ∈ H, ∀y ∈ D.                    2.3


Lemma 2.3 see 21 . Let H be a real Hilbert space. Then the following equations hold:

        i   x−y   2
                          x   2
                                  − y    2
                                             − 2 x − y, y , for all x, y ∈ H;
       ii   tx    1−t y       2
                                   t x   2
                                                1−t y       2
                                                                − t 1 − t x − y 2 , for all t ∈ 0, 1 and x, y ∈ H.

Lemma 2.4 see 22 . Let D be a nonempty, closed and convex subset of a real Hilbert space H.
Given x, y, z ∈ H and also given a ∈ R, the set

                                   v ∈D : y−v           2
                                                            ≤ x−v      2
                                                                            z, v   a                          2.4


is convex and closed.

       For solving the equilibrium problem, we assume that the bifunction F : D × D → R
satisfies the following conditions:

     A1 F x, x          0 for all x ∈ D;
     A2 F is monotone, that is, F x, y                  F y, x ≤ 0 for all x, y ∈ D;
     A3 for each x, y, z ∈ D, lim supt↓0 F tz                    1 − t x, y ≤ F x, y ;
     A4 F x, · is convex and lower semicontinuous for each x ∈ D.

Lemma 2.5 see 13 . Let D be a nonempty, closed and convex subset of a real Hilbert space H. Let
F be a bifunction from D × D to R satisfying (A1)–(A4) and let r > 0 and x ∈ H. Then, there exists
z ∈ D such that

                                                 1
                                  F z, y           y − z, z − x ≥ 0,         ∀y ∈ D.                          2.5
                                                 r

Lemma 2.6 see 18 . For r > 0, x ∈ H, defined a mapping Tr : H → D as follows:

                                                             1
                      Tr x         z ∈ D : F z, y              y − z, z − x ≥ 0, ∀y ∈ D .                     2.6
                                                             r

Then the following holds:

       1 Tr is a single value;
Discrete Dynamics in Nature and Society                                                      5

       2 Tr is firmly nonexpansive, that is, for any x, y ∈ H,


                                Tr x − Tr y   2
                                                  ≤ Tr x − Tr y, x − y ;                   2.7



       3 F Tr     EP F ;

       4 EP F is closed and convex.

      In the context of the variational inequality problem,


                        u ∈ V I D, A ⇐⇒ u            PD u − λAu ,         ∀λ > 0.          2.8


A set-valued mapping T : H → 2H is said to be monotone if for all x, y ∈ H, f ∈ T x, and
g ∈ T y imply that f − g, x − y ≥ 0. A monotone mapping T : H → H is said to be maximal
 23 if the graph G T of T is not properly contained in the graph of any other monotone
mapping. It is known that a monotone mapping is maximal if and only if for x, f ∈ H × H,
 f − g, x − y ≥ 0, ∀ y, g ∈ G T imply that f ∈ T x. Let A : D → H be an inverse strongly
monotone mapping and let ND v be the normal cone to D at v ∈ D, that is,


                           ND v    {w ∈ H : v − u, w ≥ 0, ∀u ∈ D},                         2.9


and define

                                        ⎧
                                        ⎨Av          ND v,   v ∈ D,
                                  Tv                                                     2.10
                                        ⎩∅,                    ∈
                                                             v / D.


Then T is maximal monotone and 0 ∈ T v if and only if v ∈ V I D, A see, e.g., 24 .
       In general, the fixed point set of a nonexpansive multivalued map T is not necessary
to be closed and convex see 25, Example 3.2 . In the next Lemma, we show that F T is
closed and convex under the assumption that T p {p} for all p ∈ F T .

Lemma 2.7. Let D be a closed and convex subset of a real Hilbert space H. Let T : D → CB D be a
nonexpansive multivalued map with F T / ∅ and T p {p} for each p ∈ F T . Then F T is a closed
and convex subset of D.

Proof. First, we will show that F T is closed. Let {xn } be a sequence in F T such that xn → x
as n → ∞. We have

                               d x, T x ≤ d x, xn          d xn , T x

                                         ≤ d x, xn         H T xn , T x                  2.11

                                         ≤ 2d x, xn .
6                                                                               Discrete Dynamics in Nature and Society

It follows that d x, T x  0, so x ∈ F T . Next, we show that F T is convex. Let p                                            tp1    1−
t p2 where p1 , p2 ∈ F T and t ∈ 0, 1 . Let z ∈ T p; by Lemma 2.3, we have

               p−z    2
                             t z − p1                1 − t z − p2               2


                            t z − p1     2
                                                     1 − t z − p2           2
                                                                                − t 1 − t p 1 − p2         2


                                             2                                      2
                            td z, T p1                1 − t d z, T p2                   − t 1 − t p1 − p2      2


                                                 2                                        2
                          ≤ tH T p, T p1                  1 − t H T p, T p2                   − t 1 − t p 1 − p2    2              2.12

                          ≤ t p − p1     2
                                                     1 − t p − p2           2
                                                                                − t 1 − t p 1 − p2         2


                                     2
                            t 1−t        p1 − p2           2
                                                                    1 − t t2 p1 − p2            2
                                                                                                    − t 1 − t p 1 − p2   2


                            0.

Hence p     z. Therefore, p ∈ F T .


3. Main Results
In the following theorem, we introduce a new monotone hybrid iterative scheme for finding
a common element of the set of a common fixed points of a countable family of nonexpansive
multivalued maps, the set of variational inequality, and the set of solutions of an equilibrium
problem in a Hilbert space, and we prove strong convergence theorem without the condition
 I .

Theorem 3.1. Let D be a nonempty, closed and convex subset of a real Hilbert space H. Let F be
a bifunction from D × D to R satisfying (A1)–(A4), let A : D → H be an α-inverse strongly
monotone mapping, and let Ti : D → CB D be nonexpansive multivalued maps for all i ∈ N with
       ∞
Ω:     i 1 F Ti ∩ EP F ∩ V I D, A / ∅ and Ti p       {p}, ∀p ∈ ∞1 F Ti . Assume that αi,n ∈ 0, 1
                                                                i
with lim supn → ∞ αi,n < 1 for all i ∈ N, {rn } ⊂ b, ∞ for some b ∈ 0, ∞ , and {λn } ⊂ c, d for
some c, d ∈ 0, 2α . For an initial point x0 ∈ H with C1 D and x1 PC1 x0 , let {xn }, {yn }, {si,n },
and {un } be sequences generated by

                                                 1
                             F un , y               y − un , un − xn ≥ 0,                           ∀y ∈ D,
                                                 rn
                                                  yn        PD un − λn Aun ,

                                             si,n         αi,n yn         1 − αi,n zi,n ,
                                                                                                                                    3.1
                          Ci,n   1   z ∈ Ci,n : si,n − z ≤ yn − z ≤ xn − z ,
                                                                      ∞
                                                          Cn    1          Ci,n 1 ,
                                                                     i 1

                                                 xn   1        PCn 1 x0 ,       ∀n ∈ N,

where zi,n ∈ Ti yn . Then, {xn }, {yn }, and {un } converge strongly to z0                                PΩ x0 .
Discrete Dynamics in Nature and Society                                                                    7

Proof. We split the proof into six steps.

Step 1. Show that PCn 1 x0 is well defined for every x0 ∈ H.

        Since 0 < c ≤ λn ≤ d < 2α for all n ∈ N, we get that PC I − λn A is nonexpansive for
all n ∈ N. Hence, ∞ 1 F PC I − λn A
                    n                    V I D, A is closed and convex. By Lemma 2.6 4 , we
know that EP F is closed and convex. By Lemma 2.7, we also know that ∞1 F Ti is closed
                                                                             i
                             ∞
and convex. Hence, Ω :       i 1 F Ti ∩ EP F ∩ V I D, A is a nonempty, closed and convex
set. By Lemma 2.4, we see that Ci,n 1 is closed and convex for all i, n ∈ N. This implies that
Cn 1 is also closed and convex. Therefore, PCn 1 x0 is well defined. Let p ∈ Ω and i ∈ N. From
un Trn xn , we have

                                    un − p          Trn xn − Trn p ≤ xn − p                              3.2


for every n ≥ 0. From this, we have

                              si,n − p       αi,n yn        1 − αi,n zi,n − p

                                          ≤ αi,n yn − p           1 − αi,n zi,n − p

                                          ≤ αi,n yn − p           1 − αi,n d zi,n , Ti p

                                          ≤ αi,n yn − p           1 − αi,n H Ti yn , Ti p
                                                                                                         3.3
                                          ≤ yn − p

                                             PD un − λn Aun − PD p − λn Ap

                                          ≤ un − p

                                          ≤ xn − p .


So, we have p ∈ Ci,n 1 , hence Ω ⊂ Ci,n 1 , ∀i ∈ N. This shows that Ω ⊂ Cn                  1   ⊂ Cn .

Step 2. Show that limn → ∞ xn − x0 exists.

       Since Ω is a nonempty closed convex subset of H, there exists a unique v ∈ Ω such
that

                                                       z0    PΩ x0 .                                     3.4


From xn    PCn x0 , Cn   1   ⊂ Cn and xn     1   ∈ Cn , ∀n ≥ 0, we get

                                         xn − x0 ≤ xn        1   − x0 ,    ∀n ≥ 0.                       3.5


On the other hand, as Ω ⊂ Cn , we obtain

                                         xn − x0 ≤ z0 − x0 ,              ∀n ≥ 0.                        3.6
8                                                                         Discrete Dynamics in Nature and Society

It follows that the sequence {xn } is bounded and nondecreasing. Therefore, limn → ∞ xn − x0
exists.

Step 3. Show that xn → q ∈ D as n → ∞.

         For m > n, by the definition of Cn , we see that xm                         PCm x0 ∈ Cm ⊂ Cn . By Lemma 2.2,
we get


                                     xm − xn     2
                                                     ≤ xm − x0           2
                                                                             − xn − x0 2 .                      3.7


From Step 2, we obtain that {xn } is Cauchy. Hence, there exists q ∈ D such that xn → q as
n → ∞.

Step 4. Show that q ∈ F.

         From Step 3, we get


                                                     xn   1   − xn −→ 0                                         3.8


as n → ∞. Since xn    1   ∈ Cn   1   ⊂ Cn , we have


                    si,n − xn ≤ si,n − xn            1         xn   1   − xn ≤ 2 xn      1   − xn −→ 0          3.9


as n → ∞ for all i ∈ N,


                     yn − xn ≤ yn − xn               1        xn    1   − xn ≤ 2 xn      1   − xn −→ 0         3.10


as n → ∞. Hence, yn → q as n → ∞. It follows from 3.9 and 3.10 that


                                                             1
                                     zi,n − yn                     si,n − yn −→ 0                              3.11
                                                          1 − αi,n


as n → ∞ for all i ∈ N. For each i ∈ N, we have


                          d q, Ti q ≤ q − yn                   yn − zi,n          d zi,n , Ti q

                                        ≤ q − yn               yn − zi,n          H Ti yn , Ti q               3.12

                                        ≤ q − yn               yn − zi,n           yn − q .


From 3.11 , we obtain d q, Ti q           0. Hence q ∈ F.
Discrete Dynamics in Nature and Society                                                                                9

Step 5. Show that q ∈ EP F .

      By the nonexpansiveness of PD and the inverse strongly monotonicity of A, we obtain


                           yn − p   2
                                        ≤ un − λn Aun − p − λn Ap                        2


                                        ≤ un − p      2
                                                              λn λn − 2α Aun − Ap                2

                                                                                                                    3.13
                                            Trn xn − Trn p      2
                                                                    λn λn − 2α Aun − Ap                2


                                        ≤ xn − p      2
                                                              c d − 2α Aun − Ap 2 .


This implies


                         c 2α − d Aun − Ap            2
                                                          ≤ xn − p          2
                                                                                − yn − p     2

                                                                                                                    3.14
                                                          ≤ xn − yn                 xn − p       yn − p .


It follows from 3.10 that


                                                    lim Aun − Ap                    0.                              3.15
                                                n→∞



Since PD is firmly nonexpansive, we have

             2                                                          2
    yn − p           PD un − λn Aun − PD p − λn Ap

                 ≤ un − λn Aun − p − λn Ap , yn − p
                     1                                              2
                          un − λn Aun − p − λn Ap
                     2
                                        2                                                                  2
                            yn − p          −   un − λn Aun − p − λn Ap − yn − p
                                                                                                                    3.16
                     1              2                 2                                               2
                 ≤        un − p            yn − p        −    un − yn − λn Aun − Ap
                     2
                     1              2                 2                         2
                 ≤        xn − p            yn − p        − un − yn                  2λn un − yn , Aun − Ap
                     2
                     1              2                 2                         2
                 ≤        xn − p            yn − p        − un − yn                  2λn un − yn     Aun − Ap   .
                     2


This implies that


                     yn − p   2
                                  ≤ xn − p      2
                                                    − un − yn       2
                                                                            2λn un − yn          Aun − Ap .         3.17
10                                                              Discrete Dynamics in Nature and Society

It follows that

                              un − yn   2
                                            ≤ xn − yn        xn − p      yn − p
                                                                                                   3.18
                                                2d un − yn       Aun − Ap .


From 3.10 and 3.15 , we get

                                               lim un − yn         0.                              3.19
                                              n→∞



It follows from 3.10 and 3.19 that

                                               lim un − xn         0.                              3.20
                                              n→∞



Since un   Trn xn , we have

                                            1
                         F un , y              y − un , un − xn ≥ 0,       ∀y ∈ D.                 3.21
                                            rn


From the monotonicity of F, we have

                              1
                                 y − un , un − xn ≥ F y, un ,            ∀y ∈ D,                   3.22
                              rn


hence

                                            un − xn
                                y − un ,              ≥ F y, un ,       ∀y ∈ D.                    3.23
                                              rn


From 3.20 and condition A4 , we have

                                            0 ≥ F y, q ,      ∀y ∈ D.                              3.24


For t with 0 < t ≤ 1 and y ∈ D, let yt ty                  1 − t q. Since y, q ∈ D and D is convex, then
yt ∈ D and hence F yt , q ≤ 0. So, we have

                     0   F yt , yt ≤ tF yt , y              1 − t F yt , q ≤ tF yt , y .           3.25


Dividing by t, we obtain

                                            F yt , y ≥ 0,     ∀y ∈ D.                              3.26
Discrete Dynamics in Nature and Society                                                      11

Letting t ↓ 0 and from A3 , we get

                                          F q, y ≥ 0,      ∀y ∈ D.                         3.27


Therefore, we obtain q ∈ EP F .

Step 6. Show that q ∈ V I D, A .

         Since T is the maximal monotone mapping defined by 2.10 ,
                                            ⎧
                                            ⎨Ax      ND x,     x ∈ D,
                                     Tx                                                    3.28
                                            ⎩∅,                  ∈
                                                               x / D.


For any given x, u ∈ G T , hence u − Ax ∈ ND x. It follows that

                                           x − yn , u − Ax ≥ 0.                            3.29


On the other hand, since yn     PD un − λn Aun , we have

                                    x − yn , yn − un − λn Aun        ≥ 0,                  3.30


and so

                                                 yn − un
                                      x − yn ,              Aun     ≥ 0.                   3.31
                                                   λn

From 3.29 , 3.31 , and the α-inverse monotonicity of A, we have

         x − yn , u ≥ x − yn , Ax
                                                  yn − un
                   ≥ x − yn , Ax − x − yn ,                   Aun
                                                    λn
                                                                                 yn − un   3.32
                      x − yn , Ax − Ayn          x − yn , Ayn − Aun − x − yn ,
                                                                                   λn
                                                            yn − un
                   ≥ x − yn , Ayn − Aun − x − yn ,                  .
                                                              λn

It follows that

                                    lim x − yn , u         x − q, u ≥ 0.                   3.33
                                    n→∞



Again since T is maximal monotone, hence 0 ∈ T q. This shows that q ∈ V I D, A .
12                                                                          Discrete Dynamics in Nature and Society

Step 7. Show that q     z0         PΩ x0 .

       Since xn     PCn x0 and Ω ⊂ Cn , we obtain

                                                x0 − xn , xn − p ≥ 0           ∀p ∈ Ω.                        3.34


By taking the limit in 3.34 , we obtain

                                                 x0 − q, q − p ≥ 0            ∀p ∈ Ω.                         3.35


This shows that q PΩ x0 z0 .
       From Steps 3 to 5, we obtain that {xn }, {yn }, and {un } converge strongly to z0                     PΩ x0 .
This completes the proof.

Theorem 3.2. Let D be a nonempty, closed and convex subset of a real Hilbert space H. Let Ti :
                                                                        ∞
D → CB D be nonexpansive multivalued maps for all i ∈ N with Ω :        i 1 F Ti ∩ V I D, A / ∅
                                  ∞
and Ti p     {p}, for all p ∈ i 1 F Ti . Assume that αi,n ∈ 0, 1 with lim supn → ∞ αi,n < 1 and
{λn } ⊂ c, d for some c, d ∈ 0, 2α . For an initial point x0 ∈ H with C1 D and x1 PC1 x0 , let
{xn }, {yn }, and {si,n } be sequences generated by

                             yn      PD xn − λn Axn ,
                          si,n       αi,n yn            1 − αi,n zi,n ,
                        Ci,n   1       z ∈ Ci,n : si,n − z ≤ yn − z ≤ xn − z ,
                                      ∞
                                                                                                              3.36
                         Cn    1            Ci,n 1 ,
                                      i 1
                         xn    1     PCn 1 x0 ,           ∀n ∈ N,


where zi,n ∈ Ti yn . Then, {xn } and {yn } converge strongly to z0                      PΩ x0 .

Proof. Putting F x, y        0 for all x, y ∈ D in Theorem 3.1, we obtain the desired result directly
from Theorem 3.1.

Theorem 3.3. Let D be a nonempty, closed and convex subset of a real Hilbert space H. Let Ti : D →
                                                                   ∞
CB D be nonexpansive multivalued maps for all i ∈ N with Ω :       i 1 F Ti / ∅ and Ti p    {p}, for
        ∞
all p ∈ i 1 F Ti . Assume that αi,n ∈ 0, 1 with lim supn → ∞ αi,n < 1. For an initial point x0 ∈ H
with C1 D and x1 PC1 x0 , let {xn } and {si,n } be sequences generated by

                                      si,n        αi,n xn          1 − αi,n zi,n ,
                                   Ci,n     1     {z ∈ Ci,n : sn − z ≤ xn − z },
                                                   ∞
                                                                                                              3.37
                                    Cn      1           Ci,n 1 ,
                                                  i 1
                                    xn      1     PCn 1 x0 ,        ∀n ∈ N,


where zi,n ∈ Ti yn . Then, {xn } converge strongly to z0                     PΩ x0 .
Discrete Dynamics in Nature and Society                                                                 13

Proof. Putting A     0 in Theorem 3.2, we obtain the desired result directly from Theorem 3.2.



Acknowledgments
This research is supported by the Centre of Excellence in Mathematics and the Graduate
School of Chiang Mai University.


References
 1 C. Shiau, K. K. Tan, and C. S. Wong, “Quasi-nonexpansive multi-valued maps and selections,”
   Fundamenta Mathematicae, vol. 87, pp. 109–119, 1975.
 2 N. Shahzad and H. Zegeye, “On Mann and Ishikawa iteration schemes for multi-valued maps in
   Banach spaces,” Nonlinear Analysis: Theory, Methods & Applications, vol. 71, no. 3-4, pp. 838–844, 2009.
 3 W. R. Mann, “Mean value methods in iteration,” Proceedings of the American Mathematical Society, vol.
   4, pp. 506–510, 1953.
 4 H. H. Bauschke, E. Matouˇ kov´ , and S. Reich, “Projection and proximal point methods: convergence
                                s    a
   results and counterexamples,” Nonlinear Analysis: Theory, Methods & Applications, vol. 56, no. 5, pp.
   715–738, 2004.
 5 A. Genel and J. Lindenstrauss, “An example concerning fixed points,” Israel Journal of Mathematics,
   vol. 22, no. 1, pp. 81–86, 1975.
 6 S. Reich, “Weak convergence theorems for nonexpansive mappings in Banach spaces,” Journal of
   Mathematical Analysis and Applications, vol. 67, no. 2, pp. 274–276, 1979.
 7 K. Nakajo and W. Takahashi, “Strong convergence theorems for nonexpansive mappings and
   nonexpansive semigroups,” Journal of Mathematical Analysis and Applications, vol. 279, no. 2, pp. 372–
   379, 2003.
 8 A. Tada and W. Takahashi, “Weak and strong convergence theorems for a nonexpansive mapping and
   an equilibrium problem,” Journal of Optimization Theory and Applications, vol. 133, no. 3, pp. 359–370,
   2007.
 9 K. P. R. Sastry and G. V. R. Babu, “Convergence of Ishikawa iterates for a multi-valued mapping with
   a fixed point,” Czechoslovak Mathematical Journal, vol. 55, no. 4, pp. 817–826, 2005.
10 B. Panyanak, “Mann and Ishikawa iterative processes for multivalued mappings in Banach spaces,”
   Computers & Mathematics with Applications, vol. 54, no. 6, pp. 872–877, 2007.
11 Y. Song and H. Wang, “Erratum to Mann and Ishikawa iterative process for multivalued mappings
   in Banach spaces,” Comput. Math. Appl., vol. 55, no. 6, pp. 2999–3002, 2008.
12 F. E. Browder and W. V. Petryshyn, “Construction of fixed points of nonlinear mappings in Hilbert
   space,” Journal of Mathematical Analysis and Applications, vol. 20, pp. 197–228, 1967.
13 E. Blum and W. Oettli, “From optimization and variational inequalities to equilibrium problems,” The
   Mathematics Student, vol. 63, no. 1–4, pp. 123–145, 1994.
14 L.-C. Ceng and J.-C. Yao, “A hybrid iterative scheme for mixed equilibrium problems and fixed point
   problems,” Journal of Computational and Applied Mathematics, vol. 214, no. 1, pp. 186–201, 2008.
15 P. Cholamjiak, “A hybrid iterative scheme for equilibrium problems, variational inequality problems,
   and fixed point problems in Banach spaces,” Fixed Point Theory and Applications, vol. 2009, Article ID
   719360, 18 pages, 2009.
16 P. Cholamjiak and S. Suantai, “A new hybrid algorithm for variational inclusions, generalized
   equilibrium problems, and a finite family of quasi-nonexpansive mappings,” Fixed Point Theory and
   Applications, vol. 2009, Article ID 350979, 20 pages, 2009.
17 W. Cholamjiak and S. Suantai, “Monotone hybrid projection algorithms for an infinitely countable
   family of Lipschitz generalized asymptotically quasi-nonexpansive mappings,” Abstract and Applied
   Analysis, vol. 2009, Article ID 297565, 16 pages, 2009.
18 P. L. Combettes and S. A. Hirstoaga, “Equilibrium programming in Hilbert spaces,” Journal of
   Nonlinear and Convex Analysis, vol. 6, no. 1, pp. 117–136, 2005.
19 A. Kangtunyakarn and S. Suantai, “Hybrid iterative scheme for generalized equilibrium problems
   and fixed point problems of finite family of nonexpansive mappings,” Nonlinear Analysis: Hybrid
   Systems, vol. 3, no. 3, pp. 296–309, 2009.
14                                                        Discrete Dynamics in Nature and Society

20 J.-W. Peng, Y.-C. Liou, and J.-C. Yao, “An iterative algorithm combining viscosity method with parallel
   method for a generalized equilibrium problem and strict pseudocontractions,” Fixed Point Theory and
   Applications, vol. 2009, Article ID 794178, 21 pages, 2009.
21 G. Marino and H.-K. Xu, “Weak and strong convergence theorems for strict pseudo-contractions in
   Hilbert spaces,” Journal of Mathematical Analysis and Applications, vol. 329, no. 1, pp. 336–346, 2007.
22 T.-H. Kim and H.-K. Xu, “Strong convergence of modified Mann iterations for asymptotically
   nonexpansive mappings and semigroups,” Nonlinear Analysis: Theory, Methods & Applications, vol.
   64, no. 5, pp. 1140–1152, 2006.
23 R. T. Rockafellar, “On the maximality of sums of nonlinear monotone operators,” Transactions of the
   American Mathematical Society, vol. 149, pp. 75–88, 1970.
24 H. Iiduka and W. Takahashi, “Strong convergence theorems for nonexpansive mappings and inverse-
   strongly monotone mappings,” Nonlinear Analysis: Theory, Methods & Applications, vol. 61, no. 3, pp.
   341–350, 2005.
25 A. R. Khan, “Properties of fixed point set of a multivalued map,” Journal of Applied Mathematics and
   Stochastic Analysis, vol. 2005, no. 3, pp. 323–331, 2005.

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  • 1. Hindawi Publishing Corporation Discrete Dynamics in Nature and Society Volume 2010, Article ID 349158, 14 pages doi:10.1155/2010/349158 Research Article A Hybrid Method for a Countable Family of Multivalued Maps, Equilibrium Problems, and Variational Inequality Problems Watcharaporn Cholamjiak1, 2 and Suthep Suantai1, 2 1 Department of Mathematics, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand 2 PERDO National Centre of Excellence in Mathematics, Faculty of Science, Mahidol University, Bangkok 10400, Thailand Correspondence should be addressed to Suthep Suantai, scmti005@chiangmai.ac.th Received 26 January 2010; Accepted 21 April 2010 Academic Editor: Binggen Zhang Copyright q 2010 W. Cholamjiak and S. Suantai. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. We introduce a new monotone hybrid iterative scheme for finding a common element of the set of common fixed points of a countable family of nonexpansive multivalued maps, the set of solutions of variational inequality problem, and the set of the solutions of the equilibrium problem in a Hilbert space. Strong convergence theorems of the purposed iteration are established. 1. Introduction Let D be a nonempty convex subset of a Banach spaces E. Let F be a bifunction from D × D to R, where R is the set of all real numbers. The equilibrium problem for F is to find x ∈ D such that F x, y ≥ 0 for all y ∈ D. The set of such solutions is denoted by EP F . The set D is called proximal if for each x ∈ E, there exists an element y ∈ D such that x − y d x, D , where d x, D inf{ x − z : z ∈ D}. Let CB D , K D , and P D denote the families of nonempty closed bounded subsets, nonempty compact subsets, and nonempty proximal bounded subsets of D, respectively. The Hausdorff metric on CB D is defined by H A, B max sup d x, B , sup d y, A 1.1 x∈A y∈B for A, B ∈ CB D . A single-valued map T : D → D is called nonexpansive if T x−T y ≤ x−y for all x, y ∈ D. A multivalued map T : D → CB D is said to be nonexpansive if H T x, T y ≤
  • 2. 2 Discrete Dynamics in Nature and Society x − y for all x, y ∈ D. An element p ∈ D is called a fixed point of T : D → D resp., T : D → CB D if p T p resp., p ∈ T p . The set of fixed points of T is denoted by F T . The mapping T : D → CB D is called quasi-nonexpansive 1 if F T / ∅ and H T x, T p ≤ x − p for all x ∈ D and all p ∈ F T . It is clear that every nonexpansive multivalued map T with F T / ∅ is quasi-nonexpansive. But there exist quasi-nonexpansive mappings that are not nonexpansive; see 2 . The mapping T : D → CB D is called hemicompact if, for any sequence {xn } in D such that d xn , T xn → 0 as n → ∞, there exists a subsequence {xnk } of {xn } such that xnk → p ∈ D. We note that if D is compact, then every multivalued mapping T : D → CB D is hemicompact. A mapping T : D → CB D is said to satisfy Condition (I) if there is a nondecreasing function f : 0, ∞ → 0, ∞ with f 0 0, f r > 0 for r ∈ 0, ∞ such that d x, T x ≥ f d x, F T 1.2 for all x ∈ D. In 1953, Mann 3 introduced the following iterative procedure to approximate a fixed point of a nonexpansive mapping T in a Hilbert space H: xn 1 αn xn 1 − αn T xn , ∀n ∈ N, 1.3 where the initial point x0 is taken in C arbitrarily and {αn } is a sequence in 0, 1 . However, we note that Mann’s iteration process 1.3 has only weak convergence, in general; for instance, see 4–6 . In 2003, Nakajo and Takahashi 7 introduced the method which is the so-called CQ method to modify the process 1.3 so that strong convergence is guaranteed. They also proved a strong convergence theorem for a nonexpansive mapping in a Hilbert space. Recently, Tada and Takahashi 8 proposed a new iteration for finding a common element of the set of solutions of an equilibrium problem and the set of fixed points of a nonexpansive mapping T in a Hilbert space H. In 2005, Sastry and Babu 9 proved that the Mann and Ishikawa iteration schemes for multivalued map T with a fixed point p converge to a fixed point q of T under certain conditions. They also claimed that the fixed point q may be different from p. More precisely, they proved the following result for nonexpansive multivalued map with compact domain. In 2007, Panyanak 10 extended the above result of Sastry and Babu 9 to uniformly convex Banach spaces but the domain of T remains compact. Later, Song and Wang 11 noted that there was a gap in the proofs of Theorem 3.1 10 and Theorem 5 9 . They further solved/revised the gap and also gave the affirmative answer to Panyanak 10 question using the following Ishikawa iteration scheme. In the main results, domain of T is still compact, which is a strong condition see 11, Theorem 1 and T satisfies condition I see 11, Theorem 1 . In 2009, Shahzad and Zegeye 2 extended and improved the results of Panyanak 10 , Sastry and Babu 9 , and Song and Wang 11 to quasi-nonexpansive multivalued maps. They also relaxed compactness of the domain of T and constructed an iteration scheme which removes the restriction of T , namely, T p {p} for any p ∈ F T . The results provided an affirmative answer to Panyanak 10 question in a more general setting. In the main results,
  • 3. Discrete Dynamics in Nature and Society 3 T satisfies Condition I see 2, Theorem 2.3 and T is hemicompact and continuous see 2, Theorem 2.5 . A mapping A : D → H is called α-inverse-strongly monotone 12 if there exists a positive real number α such that Ax − Ay, x − y ≥ α Ax − Ay 2 , ∀x, y ∈ D. 1.4 Remark 1.1. It is easy to see that if A : D → H is α-inverse-strongly monotone, then it is a 1/α -Lipschitzian mapping. Let A : D → H be a mapping. The classical variational inequality problem is to find a u ∈ D such that Au, v − u ≥ 0, ∀v ∈ D. 1.5 The set of solutions of variational inequality 3.9 is denoted by V I D, A . Question. How can we construct an iteration process for finding a common element of the set of solutions of an equilibrium problem, the set of solutions of a variational inequality problem, and the set of common fixed points of nonexpansive multivalued maps ? In the recent years, the problem of finding a common element of the set of solutions of equilibrium problems and the set of fixed points of single-valued nonexpansive mappings in the framework of Hilbert spaces and Banach spaces has been intensively studied by many authors; for instance, see 8, 13–20 and the references cited theorems. In this paper, we introduce a monotone hybrid iterative scheme for finding a common element of the set of a common fixed points of a countable family of nonexpansive multivalued maps, the set of variational inequality, and the set of solutions of an equilibrium problem in a Hilbert space. 2. Preliminaries The following lemmas give some characterizations and a useful property of the metric projection PD in a Hilbert space. Let H be a real Hilbert space with inner product ·, · and norm · . Let D be a closed and convex subset of H. For every point x ∈ H, there exists a unique nearest point in D, denoted by PD x, such that x − PD x ≤ x − y , ∀y ∈ D. 2.1 PD is called the metric projection of H onto D. We know that PD is a nonexpansive mapping of H onto D.
  • 4. 4 Discrete Dynamics in Nature and Society Lemma 2.1 see 21 . Let D be a closed and convex subset of a real Hilbert space H and let PD be the metric projection from H onto D. Given x ∈ H and z ∈ D, then z PD x if and only if the following holds: x − z, y − z ≤ 0, ∀y ∈ D. 2.2 Lemma 2.2 see 7 . Let D be a nonempty, closed and convex subset of a real Hilbert space H and PD : H → D the metric projection from H onto D. Then the following inequality holds: y − PD x 2 x − PD x 2 ≤ x − y 2, ∀x ∈ H, ∀y ∈ D. 2.3 Lemma 2.3 see 21 . Let H be a real Hilbert space. Then the following equations hold: i x−y 2 x 2 − y 2 − 2 x − y, y , for all x, y ∈ H; ii tx 1−t y 2 t x 2 1−t y 2 − t 1 − t x − y 2 , for all t ∈ 0, 1 and x, y ∈ H. Lemma 2.4 see 22 . Let D be a nonempty, closed and convex subset of a real Hilbert space H. Given x, y, z ∈ H and also given a ∈ R, the set v ∈D : y−v 2 ≤ x−v 2 z, v a 2.4 is convex and closed. For solving the equilibrium problem, we assume that the bifunction F : D × D → R satisfies the following conditions: A1 F x, x 0 for all x ∈ D; A2 F is monotone, that is, F x, y F y, x ≤ 0 for all x, y ∈ D; A3 for each x, y, z ∈ D, lim supt↓0 F tz 1 − t x, y ≤ F x, y ; A4 F x, · is convex and lower semicontinuous for each x ∈ D. Lemma 2.5 see 13 . Let D be a nonempty, closed and convex subset of a real Hilbert space H. Let F be a bifunction from D × D to R satisfying (A1)–(A4) and let r > 0 and x ∈ H. Then, there exists z ∈ D such that 1 F z, y y − z, z − x ≥ 0, ∀y ∈ D. 2.5 r Lemma 2.6 see 18 . For r > 0, x ∈ H, defined a mapping Tr : H → D as follows: 1 Tr x z ∈ D : F z, y y − z, z − x ≥ 0, ∀y ∈ D . 2.6 r Then the following holds: 1 Tr is a single value;
  • 5. Discrete Dynamics in Nature and Society 5 2 Tr is firmly nonexpansive, that is, for any x, y ∈ H, Tr x − Tr y 2 ≤ Tr x − Tr y, x − y ; 2.7 3 F Tr EP F ; 4 EP F is closed and convex. In the context of the variational inequality problem, u ∈ V I D, A ⇐⇒ u PD u − λAu , ∀λ > 0. 2.8 A set-valued mapping T : H → 2H is said to be monotone if for all x, y ∈ H, f ∈ T x, and g ∈ T y imply that f − g, x − y ≥ 0. A monotone mapping T : H → H is said to be maximal 23 if the graph G T of T is not properly contained in the graph of any other monotone mapping. It is known that a monotone mapping is maximal if and only if for x, f ∈ H × H, f − g, x − y ≥ 0, ∀ y, g ∈ G T imply that f ∈ T x. Let A : D → H be an inverse strongly monotone mapping and let ND v be the normal cone to D at v ∈ D, that is, ND v {w ∈ H : v − u, w ≥ 0, ∀u ∈ D}, 2.9 and define ⎧ ⎨Av ND v, v ∈ D, Tv 2.10 ⎩∅, ∈ v / D. Then T is maximal monotone and 0 ∈ T v if and only if v ∈ V I D, A see, e.g., 24 . In general, the fixed point set of a nonexpansive multivalued map T is not necessary to be closed and convex see 25, Example 3.2 . In the next Lemma, we show that F T is closed and convex under the assumption that T p {p} for all p ∈ F T . Lemma 2.7. Let D be a closed and convex subset of a real Hilbert space H. Let T : D → CB D be a nonexpansive multivalued map with F T / ∅ and T p {p} for each p ∈ F T . Then F T is a closed and convex subset of D. Proof. First, we will show that F T is closed. Let {xn } be a sequence in F T such that xn → x as n → ∞. We have d x, T x ≤ d x, xn d xn , T x ≤ d x, xn H T xn , T x 2.11 ≤ 2d x, xn .
  • 6. 6 Discrete Dynamics in Nature and Society It follows that d x, T x 0, so x ∈ F T . Next, we show that F T is convex. Let p tp1 1− t p2 where p1 , p2 ∈ F T and t ∈ 0, 1 . Let z ∈ T p; by Lemma 2.3, we have p−z 2 t z − p1 1 − t z − p2 2 t z − p1 2 1 − t z − p2 2 − t 1 − t p 1 − p2 2 2 2 td z, T p1 1 − t d z, T p2 − t 1 − t p1 − p2 2 2 2 ≤ tH T p, T p1 1 − t H T p, T p2 − t 1 − t p 1 − p2 2 2.12 ≤ t p − p1 2 1 − t p − p2 2 − t 1 − t p 1 − p2 2 2 t 1−t p1 − p2 2 1 − t t2 p1 − p2 2 − t 1 − t p 1 − p2 2 0. Hence p z. Therefore, p ∈ F T . 3. Main Results In the following theorem, we introduce a new monotone hybrid iterative scheme for finding a common element of the set of a common fixed points of a countable family of nonexpansive multivalued maps, the set of variational inequality, and the set of solutions of an equilibrium problem in a Hilbert space, and we prove strong convergence theorem without the condition I . Theorem 3.1. Let D be a nonempty, closed and convex subset of a real Hilbert space H. Let F be a bifunction from D × D to R satisfying (A1)–(A4), let A : D → H be an α-inverse strongly monotone mapping, and let Ti : D → CB D be nonexpansive multivalued maps for all i ∈ N with ∞ Ω: i 1 F Ti ∩ EP F ∩ V I D, A / ∅ and Ti p {p}, ∀p ∈ ∞1 F Ti . Assume that αi,n ∈ 0, 1 i with lim supn → ∞ αi,n < 1 for all i ∈ N, {rn } ⊂ b, ∞ for some b ∈ 0, ∞ , and {λn } ⊂ c, d for some c, d ∈ 0, 2α . For an initial point x0 ∈ H with C1 D and x1 PC1 x0 , let {xn }, {yn }, {si,n }, and {un } be sequences generated by 1 F un , y y − un , un − xn ≥ 0, ∀y ∈ D, rn yn PD un − λn Aun , si,n αi,n yn 1 − αi,n zi,n , 3.1 Ci,n 1 z ∈ Ci,n : si,n − z ≤ yn − z ≤ xn − z , ∞ Cn 1 Ci,n 1 , i 1 xn 1 PCn 1 x0 , ∀n ∈ N, where zi,n ∈ Ti yn . Then, {xn }, {yn }, and {un } converge strongly to z0 PΩ x0 .
  • 7. Discrete Dynamics in Nature and Society 7 Proof. We split the proof into six steps. Step 1. Show that PCn 1 x0 is well defined for every x0 ∈ H. Since 0 < c ≤ λn ≤ d < 2α for all n ∈ N, we get that PC I − λn A is nonexpansive for all n ∈ N. Hence, ∞ 1 F PC I − λn A n V I D, A is closed and convex. By Lemma 2.6 4 , we know that EP F is closed and convex. By Lemma 2.7, we also know that ∞1 F Ti is closed i ∞ and convex. Hence, Ω : i 1 F Ti ∩ EP F ∩ V I D, A is a nonempty, closed and convex set. By Lemma 2.4, we see that Ci,n 1 is closed and convex for all i, n ∈ N. This implies that Cn 1 is also closed and convex. Therefore, PCn 1 x0 is well defined. Let p ∈ Ω and i ∈ N. From un Trn xn , we have un − p Trn xn − Trn p ≤ xn − p 3.2 for every n ≥ 0. From this, we have si,n − p αi,n yn 1 − αi,n zi,n − p ≤ αi,n yn − p 1 − αi,n zi,n − p ≤ αi,n yn − p 1 − αi,n d zi,n , Ti p ≤ αi,n yn − p 1 − αi,n H Ti yn , Ti p 3.3 ≤ yn − p PD un − λn Aun − PD p − λn Ap ≤ un − p ≤ xn − p . So, we have p ∈ Ci,n 1 , hence Ω ⊂ Ci,n 1 , ∀i ∈ N. This shows that Ω ⊂ Cn 1 ⊂ Cn . Step 2. Show that limn → ∞ xn − x0 exists. Since Ω is a nonempty closed convex subset of H, there exists a unique v ∈ Ω such that z0 PΩ x0 . 3.4 From xn PCn x0 , Cn 1 ⊂ Cn and xn 1 ∈ Cn , ∀n ≥ 0, we get xn − x0 ≤ xn 1 − x0 , ∀n ≥ 0. 3.5 On the other hand, as Ω ⊂ Cn , we obtain xn − x0 ≤ z0 − x0 , ∀n ≥ 0. 3.6
  • 8. 8 Discrete Dynamics in Nature and Society It follows that the sequence {xn } is bounded and nondecreasing. Therefore, limn → ∞ xn − x0 exists. Step 3. Show that xn → q ∈ D as n → ∞. For m > n, by the definition of Cn , we see that xm PCm x0 ∈ Cm ⊂ Cn . By Lemma 2.2, we get xm − xn 2 ≤ xm − x0 2 − xn − x0 2 . 3.7 From Step 2, we obtain that {xn } is Cauchy. Hence, there exists q ∈ D such that xn → q as n → ∞. Step 4. Show that q ∈ F. From Step 3, we get xn 1 − xn −→ 0 3.8 as n → ∞. Since xn 1 ∈ Cn 1 ⊂ Cn , we have si,n − xn ≤ si,n − xn 1 xn 1 − xn ≤ 2 xn 1 − xn −→ 0 3.9 as n → ∞ for all i ∈ N, yn − xn ≤ yn − xn 1 xn 1 − xn ≤ 2 xn 1 − xn −→ 0 3.10 as n → ∞. Hence, yn → q as n → ∞. It follows from 3.9 and 3.10 that 1 zi,n − yn si,n − yn −→ 0 3.11 1 − αi,n as n → ∞ for all i ∈ N. For each i ∈ N, we have d q, Ti q ≤ q − yn yn − zi,n d zi,n , Ti q ≤ q − yn yn − zi,n H Ti yn , Ti q 3.12 ≤ q − yn yn − zi,n yn − q . From 3.11 , we obtain d q, Ti q 0. Hence q ∈ F.
  • 9. Discrete Dynamics in Nature and Society 9 Step 5. Show that q ∈ EP F . By the nonexpansiveness of PD and the inverse strongly monotonicity of A, we obtain yn − p 2 ≤ un − λn Aun − p − λn Ap 2 ≤ un − p 2 λn λn − 2α Aun − Ap 2 3.13 Trn xn − Trn p 2 λn λn − 2α Aun − Ap 2 ≤ xn − p 2 c d − 2α Aun − Ap 2 . This implies c 2α − d Aun − Ap 2 ≤ xn − p 2 − yn − p 2 3.14 ≤ xn − yn xn − p yn − p . It follows from 3.10 that lim Aun − Ap 0. 3.15 n→∞ Since PD is firmly nonexpansive, we have 2 2 yn − p PD un − λn Aun − PD p − λn Ap ≤ un − λn Aun − p − λn Ap , yn − p 1 2 un − λn Aun − p − λn Ap 2 2 2 yn − p − un − λn Aun − p − λn Ap − yn − p 3.16 1 2 2 2 ≤ un − p yn − p − un − yn − λn Aun − Ap 2 1 2 2 2 ≤ xn − p yn − p − un − yn 2λn un − yn , Aun − Ap 2 1 2 2 2 ≤ xn − p yn − p − un − yn 2λn un − yn Aun − Ap . 2 This implies that yn − p 2 ≤ xn − p 2 − un − yn 2 2λn un − yn Aun − Ap . 3.17
  • 10. 10 Discrete Dynamics in Nature and Society It follows that un − yn 2 ≤ xn − yn xn − p yn − p 3.18 2d un − yn Aun − Ap . From 3.10 and 3.15 , we get lim un − yn 0. 3.19 n→∞ It follows from 3.10 and 3.19 that lim un − xn 0. 3.20 n→∞ Since un Trn xn , we have 1 F un , y y − un , un − xn ≥ 0, ∀y ∈ D. 3.21 rn From the monotonicity of F, we have 1 y − un , un − xn ≥ F y, un , ∀y ∈ D, 3.22 rn hence un − xn y − un , ≥ F y, un , ∀y ∈ D. 3.23 rn From 3.20 and condition A4 , we have 0 ≥ F y, q , ∀y ∈ D. 3.24 For t with 0 < t ≤ 1 and y ∈ D, let yt ty 1 − t q. Since y, q ∈ D and D is convex, then yt ∈ D and hence F yt , q ≤ 0. So, we have 0 F yt , yt ≤ tF yt , y 1 − t F yt , q ≤ tF yt , y . 3.25 Dividing by t, we obtain F yt , y ≥ 0, ∀y ∈ D. 3.26
  • 11. Discrete Dynamics in Nature and Society 11 Letting t ↓ 0 and from A3 , we get F q, y ≥ 0, ∀y ∈ D. 3.27 Therefore, we obtain q ∈ EP F . Step 6. Show that q ∈ V I D, A . Since T is the maximal monotone mapping defined by 2.10 , ⎧ ⎨Ax ND x, x ∈ D, Tx 3.28 ⎩∅, ∈ x / D. For any given x, u ∈ G T , hence u − Ax ∈ ND x. It follows that x − yn , u − Ax ≥ 0. 3.29 On the other hand, since yn PD un − λn Aun , we have x − yn , yn − un − λn Aun ≥ 0, 3.30 and so yn − un x − yn , Aun ≥ 0. 3.31 λn From 3.29 , 3.31 , and the α-inverse monotonicity of A, we have x − yn , u ≥ x − yn , Ax yn − un ≥ x − yn , Ax − x − yn , Aun λn yn − un 3.32 x − yn , Ax − Ayn x − yn , Ayn − Aun − x − yn , λn yn − un ≥ x − yn , Ayn − Aun − x − yn , . λn It follows that lim x − yn , u x − q, u ≥ 0. 3.33 n→∞ Again since T is maximal monotone, hence 0 ∈ T q. This shows that q ∈ V I D, A .
  • 12. 12 Discrete Dynamics in Nature and Society Step 7. Show that q z0 PΩ x0 . Since xn PCn x0 and Ω ⊂ Cn , we obtain x0 − xn , xn − p ≥ 0 ∀p ∈ Ω. 3.34 By taking the limit in 3.34 , we obtain x0 − q, q − p ≥ 0 ∀p ∈ Ω. 3.35 This shows that q PΩ x0 z0 . From Steps 3 to 5, we obtain that {xn }, {yn }, and {un } converge strongly to z0 PΩ x0 . This completes the proof. Theorem 3.2. Let D be a nonempty, closed and convex subset of a real Hilbert space H. Let Ti : ∞ D → CB D be nonexpansive multivalued maps for all i ∈ N with Ω : i 1 F Ti ∩ V I D, A / ∅ ∞ and Ti p {p}, for all p ∈ i 1 F Ti . Assume that αi,n ∈ 0, 1 with lim supn → ∞ αi,n < 1 and {λn } ⊂ c, d for some c, d ∈ 0, 2α . For an initial point x0 ∈ H with C1 D and x1 PC1 x0 , let {xn }, {yn }, and {si,n } be sequences generated by yn PD xn − λn Axn , si,n αi,n yn 1 − αi,n zi,n , Ci,n 1 z ∈ Ci,n : si,n − z ≤ yn − z ≤ xn − z , ∞ 3.36 Cn 1 Ci,n 1 , i 1 xn 1 PCn 1 x0 , ∀n ∈ N, where zi,n ∈ Ti yn . Then, {xn } and {yn } converge strongly to z0 PΩ x0 . Proof. Putting F x, y 0 for all x, y ∈ D in Theorem 3.1, we obtain the desired result directly from Theorem 3.1. Theorem 3.3. Let D be a nonempty, closed and convex subset of a real Hilbert space H. Let Ti : D → ∞ CB D be nonexpansive multivalued maps for all i ∈ N with Ω : i 1 F Ti / ∅ and Ti p {p}, for ∞ all p ∈ i 1 F Ti . Assume that αi,n ∈ 0, 1 with lim supn → ∞ αi,n < 1. For an initial point x0 ∈ H with C1 D and x1 PC1 x0 , let {xn } and {si,n } be sequences generated by si,n αi,n xn 1 − αi,n zi,n , Ci,n 1 {z ∈ Ci,n : sn − z ≤ xn − z }, ∞ 3.37 Cn 1 Ci,n 1 , i 1 xn 1 PCn 1 x0 , ∀n ∈ N, where zi,n ∈ Ti yn . Then, {xn } converge strongly to z0 PΩ x0 .
  • 13. Discrete Dynamics in Nature and Society 13 Proof. Putting A 0 in Theorem 3.2, we obtain the desired result directly from Theorem 3.2. Acknowledgments This research is supported by the Centre of Excellence in Mathematics and the Graduate School of Chiang Mai University. References 1 C. Shiau, K. K. Tan, and C. S. Wong, “Quasi-nonexpansive multi-valued maps and selections,” Fundamenta Mathematicae, vol. 87, pp. 109–119, 1975. 2 N. Shahzad and H. Zegeye, “On Mann and Ishikawa iteration schemes for multi-valued maps in Banach spaces,” Nonlinear Analysis: Theory, Methods & Applications, vol. 71, no. 3-4, pp. 838–844, 2009. 3 W. R. Mann, “Mean value methods in iteration,” Proceedings of the American Mathematical Society, vol. 4, pp. 506–510, 1953. 4 H. H. Bauschke, E. Matouˇ kov´ , and S. Reich, “Projection and proximal point methods: convergence s a results and counterexamples,” Nonlinear Analysis: Theory, Methods & Applications, vol. 56, no. 5, pp. 715–738, 2004. 5 A. Genel and J. Lindenstrauss, “An example concerning fixed points,” Israel Journal of Mathematics, vol. 22, no. 1, pp. 81–86, 1975. 6 S. Reich, “Weak convergence theorems for nonexpansive mappings in Banach spaces,” Journal of Mathematical Analysis and Applications, vol. 67, no. 2, pp. 274–276, 1979. 7 K. Nakajo and W. Takahashi, “Strong convergence theorems for nonexpansive mappings and nonexpansive semigroups,” Journal of Mathematical Analysis and Applications, vol. 279, no. 2, pp. 372– 379, 2003. 8 A. Tada and W. Takahashi, “Weak and strong convergence theorems for a nonexpansive mapping and an equilibrium problem,” Journal of Optimization Theory and Applications, vol. 133, no. 3, pp. 359–370, 2007. 9 K. P. R. Sastry and G. V. R. Babu, “Convergence of Ishikawa iterates for a multi-valued mapping with a fixed point,” Czechoslovak Mathematical Journal, vol. 55, no. 4, pp. 817–826, 2005. 10 B. Panyanak, “Mann and Ishikawa iterative processes for multivalued mappings in Banach spaces,” Computers & Mathematics with Applications, vol. 54, no. 6, pp. 872–877, 2007. 11 Y. Song and H. Wang, “Erratum to Mann and Ishikawa iterative process for multivalued mappings in Banach spaces,” Comput. Math. Appl., vol. 55, no. 6, pp. 2999–3002, 2008. 12 F. E. Browder and W. V. Petryshyn, “Construction of fixed points of nonlinear mappings in Hilbert space,” Journal of Mathematical Analysis and Applications, vol. 20, pp. 197–228, 1967. 13 E. Blum and W. Oettli, “From optimization and variational inequalities to equilibrium problems,” The Mathematics Student, vol. 63, no. 1–4, pp. 123–145, 1994. 14 L.-C. Ceng and J.-C. Yao, “A hybrid iterative scheme for mixed equilibrium problems and fixed point problems,” Journal of Computational and Applied Mathematics, vol. 214, no. 1, pp. 186–201, 2008. 15 P. Cholamjiak, “A hybrid iterative scheme for equilibrium problems, variational inequality problems, and fixed point problems in Banach spaces,” Fixed Point Theory and Applications, vol. 2009, Article ID 719360, 18 pages, 2009. 16 P. Cholamjiak and S. Suantai, “A new hybrid algorithm for variational inclusions, generalized equilibrium problems, and a finite family of quasi-nonexpansive mappings,” Fixed Point Theory and Applications, vol. 2009, Article ID 350979, 20 pages, 2009. 17 W. Cholamjiak and S. Suantai, “Monotone hybrid projection algorithms for an infinitely countable family of Lipschitz generalized asymptotically quasi-nonexpansive mappings,” Abstract and Applied Analysis, vol. 2009, Article ID 297565, 16 pages, 2009. 18 P. L. Combettes and S. A. Hirstoaga, “Equilibrium programming in Hilbert spaces,” Journal of Nonlinear and Convex Analysis, vol. 6, no. 1, pp. 117–136, 2005. 19 A. Kangtunyakarn and S. Suantai, “Hybrid iterative scheme for generalized equilibrium problems and fixed point problems of finite family of nonexpansive mappings,” Nonlinear Analysis: Hybrid Systems, vol. 3, no. 3, pp. 296–309, 2009.
  • 14. 14 Discrete Dynamics in Nature and Society 20 J.-W. Peng, Y.-C. Liou, and J.-C. Yao, “An iterative algorithm combining viscosity method with parallel method for a generalized equilibrium problem and strict pseudocontractions,” Fixed Point Theory and Applications, vol. 2009, Article ID 794178, 21 pages, 2009. 21 G. Marino and H.-K. Xu, “Weak and strong convergence theorems for strict pseudo-contractions in Hilbert spaces,” Journal of Mathematical Analysis and Applications, vol. 329, no. 1, pp. 336–346, 2007. 22 T.-H. Kim and H.-K. Xu, “Strong convergence of modified Mann iterations for asymptotically nonexpansive mappings and semigroups,” Nonlinear Analysis: Theory, Methods & Applications, vol. 64, no. 5, pp. 1140–1152, 2006. 23 R. T. Rockafellar, “On the maximality of sums of nonlinear monotone operators,” Transactions of the American Mathematical Society, vol. 149, pp. 75–88, 1970. 24 H. Iiduka and W. Takahashi, “Strong convergence theorems for nonexpansive mappings and inverse- strongly monotone mappings,” Nonlinear Analysis: Theory, Methods & Applications, vol. 61, no. 3, pp. 341–350, 2005. 25 A. R. Khan, “Properties of fixed point set of a multivalued map,” Journal of Applied Mathematics and Stochastic Analysis, vol. 2005, no. 3, pp. 323–331, 2005.