I have to prove that for all k,m,n [tex]\in[/tex] [tex]N[/tex] that if m+k = n+k, then m=n. The problem mentions that I must prove this by induction. I did the base case k = 0: If m+0 = n+0, by identity m=n. Then I attempt to show that m+1 = n+1 implies m=n, but I am stuck, I don't see how induction can be used to prove this and then next predicate that m+k = n+k implies m=n. Any help would be greatly appreciated, and thanks in advance.