IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
sfa doc ycomb factorial typing21 1. x :
2. x1:. x1<x Y((f,x. if x=0 1 else xf(x-1) fi),x1)
Y((f,x. if x=0 1 else xf(x-1) fi),x)
By:
Compute
CoY((f,x. if x=0 1 else xf(x-1) fi),x)
Co*
Coif x=0 1 else xY((f,x. if x=0 1 else xf(x-1) fi),x-1) fi