Homework Statement
Let X= N x N. Define a relation R on X by (x,y)R(z,w) if xw=yz. Then R is an equivalence relation.
Define "+" and "x"(multiplication) on the set X/R of equivalence classes by:
[x,y] "+" [z,w] = [xw + yz,yw]
[x,y] "x" [z,w] = [xz.yw].
Prove that each of the operations is...