IF YOU CAN SEE THIS go to http://www.cs.cornell.edu/Info/People/sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
sublist weakening T:Type, L1,L2:T List. L1 = L2L1L2
By:
Unfold `sublist` 0 THEN InstConcl [i.i] THEN Reduce 0
THEN
Try (Complete (WeakSubstFor L2 0))
THEN
Try Analyze
THEN
Try Auto