Def Inj(A; B; f) == a1,a2:A. f(a1) = f(a2)  B  a1 = a2

is mentioned by

Thm* n,m:, f:(nm). Inj(n; m; f)  nm	[pigeon-hole]
Thm* k,m:. (f:(km). Inj(k; m; f))  km	[injection_le]
Thm* k,m:, f:(km). increasing(f;k)  Inj(k; m; f)	[increasing_inj]

In prior sections: fun 1

Try larger context: MarkB generic IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html