IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
iseg select211 1. T : Type
2. T List
3. u : T 4. v : T List
5. l2:T List. vl2 ||v||||l2|| & (i:. i<||v|| v[i] = l2[i])
6. T List
7. [u / v] nil
||v||+10 & (i:. i<||v||+1 [u / v][i] = nil[i])