What does the logic statement "F = AB" mean? Bitwise A AND B?

Yes, when written as multiplication in normal math, it means AND in Boolean logic. This does make some sense when you think about it. Make a truth table of multiplying two value that can be either 0 or 1. The result is 0 except when both are 1, then the result is 1. That's exactly what AND does.

This logic doesn't really follow for "+", unless you consider 0 FALSE and anything else TRUE.

You are right AB mean A AND B . It is faster to write AB than A dot B or A AND B