Nuprl - Some Definitions

iff	`Def P Q == (P Q) & (P Q)` `Thm* A,B:Prop. (A B) Prop`
one_one_corr	`Def A ~ B == f:(AB), g:(BA). InvFuns(A; B; f; g)` `Thm* A,B:Type. (A ~ B) Prop`
rev_implies	`Def P Q == Q P` `Thm* A,B:Prop. (A B) Prop`
inv_funs	`Def InvFuns(A; B; f; g) == g o f = Id & f o g = Id` `Thm* A,B:Type, f:(AB), g:(BA). InvFuns(A; B; f; g) Prop`
tidentity	`Def Id == Id` `Thm* A:Type. Id AA`
compose	`Def (f o g)(x) == f(g(x))` `Thm* A,B,C:Type, f:(BC), g:(AB). f o g AC`
identity	`Def Id(x) == x` `Thm* A:Type. Id AA`

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