This document discusses two entities, A and B, and their relationship to concepts C, P, N, and M. It appears A and B are separate but related topics that both connect to broader ideas C, P, N, and M in some way. The document does not provide enough contextual information to offer more specifics in the summary.

3. A
C
B

4. A
C
B

5. P
N
M

6. P
N
M