IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
list iso211 1. 'a : S
2. x' : 'a List
3. x'' : 'a List
4. <n:. if n<||x'|| then x'[n] else arb('a) fi ,||x'||>
4. =
4. <n:. if n<||x''|| then x''[n] else arb('a) fi ,||x''||>
x' = x''