IF YOU CAN SEE THIS go to http://www.cs.cornell.edu/Info/People/sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
iseg append T:Type, l1,l2,l3:T List. l1l2l1l2 @ l3
By:
Unfold `iseg` 0 THEN ExRepD THEN InstConcl [l @ l3] THEN WeakSubstFor l2 0
THEN
RWO Thm*as,bs,cs:T List. ((as @ bs) @ cs) = (as @ (bs @ cs)) 0
Generated subgoals:
None
About:
IF YOU CAN SEE THIS go to http://www.cs.cornell.edu/Info/People/sfa/Nuprl/Shared/Xindentation_hack_doc.html
T:Type, l1,l2,l3:T List. l1 
l2 
l1 
