Background: I'm a philosophy student. I'm comfortable with math, but don't have much of a background in it. One of the topics I'm writing about (I-relation in theories of identity) closely mirrors concepts in math. One of those is reflexivity.
My attempt to answer the question: I read the Reflexivity article on Wikipedia, but I'm still foggy on the idea. I get that 1=1 is reflexive, and 1<2 is not. I understand that 1=1 is relating one to one, but it seems so redundant that I can't imagine it being often used in math - but I believe that it is - so I must be missing something. Also, I read that the 'divides' relationship (2 divides 4) is reflexive. I don't see how that is reflexive.
- How can something be related to itself?
- Why is reflexivity a useful concept?
- How is the divides relationship reflexive?
An abstract explanation and concrete example would be helpful.