1. The problem statement, all variables and given/known data a function 'd' is a closed binary operation on a set called 'T'. There is an identity element named j. for all elements a, b, and c in the set 'T', we have d(a, d(b,c)) = d((a,c), b) can anyone help me show that d is commutative and associative? 2. Relevant equations f is commutative if function f(s,u) = f(u,s) f is associative if function f(x, f(y,z)) = f((x,y), z) q is an identity element if function f(q,a) = a and f(a,q) = a. 3. The attempt at a solution The attempt began with proving commutative, but ended shortly after because there are three elements in the problem and as far as i know commutative only uses 2.