Who Cites productively infinite?
productively_infinite	Def  Infinite(A) == ( inj A)
	Thm*  A:Type. Infinite(A)  Prop
nat	Def   == {i:| 0i }
	Thm*    Type
injection_type	Def  A inj B == {f:(AB)| Inj(A; B; f) }
	Thm*  A,B:Type. A inj B  Type
le	Def  AB == B<A
	Thm*  i,j:. (ij)  Prop
inject	Def  Inj(A; B; f) == a1,a2:A. f(a1) = f(a2)  B  a1 = a2
	Thm*  A,B:Type, f:(AB). Inj(A; B; f)  Prop
not	Def  A == A  False
	Thm*  A:Prop. (A)  Prop

Syntax:

Infinite(A)

has structure:

productively_infinite(A)

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