x~y just means that x and y are in the same set of the partition. So for example 1~3 and 4~4 would both be true, but not 2~5 because 2 and 5 are in different sets in P.
Let P={{1,3},{2},{4,5}} be a partition of {1,2,3,4,5}. For the corresponding equivalence relation ~, which of the following are true?
a) 4~5
b) 3~3
c) 1~2
d) 5~1
What does this even mean? if you could show me a couple I could probably figure out the rest of them.