Some definitions of interest.
int_seg	Def  {i..j} == {k:| i  k < j }
	Thm*  m,n:. {m..n}  Type
lelt	Def  i  j < k == ij & j<k
le	Def  AB == B<A
	Thm*  i,j:. (ij)  Prop
nat_plus	Def   == {i:| 0<i }
	Thm*    Type

About: IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html