Hungerford’s Section 2.1
Thus far in Hungerford’s book I have yet to encounter something super difficult to understand. Proof techniques, of course, shall return to my memory as I study and practice but the material, especially in Section 2.1 is very straight forward. The most difficult part I have is trying to see how this shall be applicable. Congruence (thus far in my physics education) has never appeared and so I struggle to see how it is applicable.
The real question I should be asking is “What does it mean for two numbers to be congruent?”
Congruence classes bring up the idea of disjoint and identical. Why is it so significant that there is no overlap between sets of Congruence classes?