1. The problem statement, all variables and given/known data Prove that when R and S are equivalence relations, then SR is equivalance relation when SR=RS. 2. Relevant equations 3. The attempt at a solution I want to know what sets should i take for the relations ? is it ok when i take R a a subset of X x Y and S as a subset of Y and Z or should i take it some other way? then SR is a subset of X x Z ? am i moving right? also when tring to solve this problem I found that x has to be equal to y when SR = RS.. Thank you!