IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
assert-w-first12111 1. the_w : World
2. i : Id
3. t : 4. 0<t 5. t=0
6. isnull(a(i;t-1))
7. first(<i,t-1>) 8. first(<i,t-1>)
9. t':. t'<t-1 isnull(a(i;t'))
t':. t'<t isnull(a(i;t'))