Nuprl - Some Definitions

pi1	`Def 1of(t) == t.1` `Thm* B:(AType), p:a:AB(a). 1of(p) A`
exp	`Def (rec) (basepower) == if power=0 1 else base(basepower-1) fi Thm* n,k:. (nk)` `Thm* n,k:. (nk)`
int_seg	`Def {i..j} == {k:\| i k < j}` `Thm* m,n:. {m..n} Type`
nat	`Def == {i:\| 0i}` `Thm* Type`
lelt	`Def i j < k == ij & j < k`
le	`Def AB == B < A` `Thm* i,j:. ij Prop`
not	`Def A == A False` `Thm* (A) Prop`
pi2	`Def 2of(t) == t.2` `Thm* B:(AType), p:a:AB(a). 2of(p) B(1of(p))`
eq_int	`Def i=j == if i=jtrue; false fi` `Thm* i,j:. i=j`