Although decidely off-subject, this discussion has now become interesting. IMHO, Ab's statement:
ab wrote:logic is a branch of mathematics, your friend is not wrong.
is an incorrect statement, if we accept the common definitions of logic.
In common terms, logic, is a part of philosophy dedicated to the study of reasoning and inference. There is a part of mathematics called "Mathematical Logic", but that is only a subset of Logic.
Philosophers will quibble the exact meanings. To avoid any of this, consider the relationship of mathematics and logic. As a case in point, let us pretend that I am a primitive human from yesteryear, or possibly a pre-human, or even an animal, and let us presume that I know nothing about maths. However, from simple experience, I know that if I wait below certain trees, snakes are likely to descend and bite me, so therefore I must not hang around under those trees, and I will avoid doing so. In common terms, where is the mathematics in the fact that I have deduced that it is not a good idea to wait around under these trees? As there is none, I have to deduce that the original statement is incorrect. I am sure that everyone can think of countless better examples.
Michael