Nuprl - Some Definitions

finite	`Def Fin(s) == n:, f:(ns). Bij(n;s;f)` `Thm* Fin(T) Prop`
int_seg	`Def {i..j} == {k:\| i k < j}` `Thm* m,n:. {m..n} Type`
biject	`Def Bij(A;B;f) == Inj(A;B;f) & Surj(A;B;f)` `Thm* f:(AB). Bij(A;B;f) Prop`
nat	`Def == {i:\| 0i}` `Thm* Type`
lelt	`Def i j < k == ij & j < k`
surject	`Def Surj(A;B;f) == b:B. a:A. f(a) = b` `Thm* f:(AB). Surj(A;B;f) Prop`
inject	`Def basic Inj(A;B;f) == a1,a2:A. f(a1) = f(a2) B a1 = a2` `Thm* f:(AB). Inj(A;B;f) Prop`
le	`Def AB == B < A` `Thm* i,j:. ij Prop`
not	`Def A == A False` `Thm* (A) Prop`