IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
sum axiom 'c,'b,'a:S, f:('a'c), g:('b'c).
(h:(('a+'b)'c).
(h o (x:'a. inl(x)) = f'a'c & h o (x:'b. inr(x)) = g'b'c)
& (h,y:(('a+'b)'c).
& (h o (x:'a. inl(x)) = f'a'c & h o (x:'b. inr(x)) = g'b'c & (& y o (x:'a. inl(x)) = f'a'c & (& y o (x:'b. inr(x)) = g'b'c & ( & (h = y)