Homework Statement
Let (S,\cdot ) be an algebraic structure where the operation \cdot is associative and commutative and also the following axiom is satisfied:
\forall x,y\in S,\exists z\in S: zx = y\ \ (1)
Prove that if for every a,b,c\in S, ac = bc, then a=b.
Homework EquationsThe Attempt...