Nuprl - Some Definitions

eq_int	`Def i=j == if i=jtrue; false fi` `Thm* i,j:. i=j`
assert	`Def b == if b True else False fi` `Thm* b:. b Prop`
iff	`Def P Q == (P Q) & (P Q)` `Thm* (A B) Prop`
guard	`Def {T} == T` `Thm* {T} Type`
bfalse	`Def false ==` `Thm* false`
btrue	`Def true ==` `Thm* true`
ifthenelse	`Def if b t else f fi == dec(b ; t; f)` `Thm* b:, A:Type, p,q:A. if b p else q fi A`
rev_implies	`Def P Q == Q P` `Thm* (A B) Prop`