Nuprl - Proof: fun with inv2 is inj 1

IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At: fun with inv2 is inj 1

1. A : Type
2. B : Type
3. f : A

B
4. g : B

A
5.

x:A. g(f(x)) = x
6.

y:B. f(g(y)) = y

Inj(A; B; f)

By:

Analyze

Generated subgoal:

1 7. a1 : A
8. a2 : A
9. f(a1) = f(a2)
a1 = a2
2 steps

About:

IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html