IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
nsub inj fill typing112 1. a :
2. b :
3. j : b 4. f : (a-1){x:b| x = j }
5. Inj((a-1); {x:b| x = j }; f)
6. (i.if i=a-1 j else f(i) fi) ab Inj(a; b; i.if i=a-1 j else f(i) fi)