IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
one one corr rel vs invfuns111112a1 1. A : Type
2. B : Type
3. R : ABProp
4. x:A. !y:B. R(x;y)
5. y:B. !x:A. R(x;y)
6. f : AB 7. x:A. R(x;f(x))
8. g : BA 9. y:B. R(g(y);y)
10. y : B 11. !u:B. R(g(y);u)
f(g(y)) = y
By:
FwdThru:
Thm*P:(AProp). (!u:A. P(u)) (y,z:A. P(y) P(z) y = z)
on [ Hyp:-1 ]
Using:[f(g(y)) | y]