IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
proper sublist length1 1. T : Type
2. L1 : T List
3. L2 : T List
4. L1L2 5. ||L1|| = ||L2||
6. i :
7. i<||L1||
L1[i] = L2[i]
By:
AllHyps (Unfold `sublist`) THEN ExRepD THEN AllHyps (InstHyp [i])