Nuprl - Proof: bij imp exists inv version2 1 2 1 1

IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At: bij imp exists inv version2 1 2 1 1

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

B
4. Inj(A; B; f)
5. Surj(A; B; f)
6.

b:B.

!a:A. f(a) = b
7. g : B

A
8.

b:B. f(g(b)) = b
9. x : A

g(f(x)) = x

By:	BackThru: Hyp:4

Generated subgoal:

1 f(g(f(x))) = f(x)
1 step

About:

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