The document presents a proof by contradiction of a theorem regarding some mathematical concept. It assumes the theorem is false and derives a contradiction using definitions and previously established results. This implies the original assumption was incorrect, proving the theorem is indeed true. A second method of proof is also provided using similar logical steps and references to definitions and axioms.

2. TEOREMA 1.8D
Jika
 Jika

3. PEMBUKTIAN:
i

1.
2.
 Sehingga diperoleh
 Jadi pengandaian diatas tidak benar (salah). Harusnya

4. CARA KEDUA
...............(defenisi 1.1g)
.....................(defenisi 1.2b)

5. .........................(A8)
................................(A10)
....................(T.1.4a)
.........................(A9)
..............................(T.1.4a)

6. 





7. CARA KEDUA
............(defenisi 1.1g)
.............(defenisi 1.2b)

8. ........................(A8)
.....................(A10)
.........................(T.1.4a)
.....................(A9)
........................(T.1.4a)