IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
rel exp list1 1. T : Type
2. R : TTProp
x,y:T.
x = y (L:T List.
(||L|| = 1 & L[0] = x & last(L) = y & (i:0. L[i] RL[(i+1)]))
By:
Unfold `last` 0 THEN Try (InstConcl [[x]] THEN Reduce 0) THEN ExRepD