Is there any certain ways of thinking of these examples? Or just guess and try?
a) Reflexive and symmetric, but not transitive
= abs(a-b) < 1... right? any other example?
b) Reflexive but neither symmetric nor transitive
= a-b < 1, any other type?
c) Symmetric, but neither reflexive nor transitive
= abs(a-b) = 1, any other?
d) Transitive, but neiter reflexive nor symmetric
= a < b
any other examples will be appreciated, thanks