Nuprl - Proof: fun description

IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
Existence of functions through description.

A:Type, B:(A

Type), P:(x:A

B(x)

Prop).

(

x:A.

!y:B(x). P(x,y))

(

f:(x:A

B(x)).

x:A. P(x,f(x)))

By:	Def of !y:B(x). P(x,y)

Generated subgoal:

1 1. A : Type
2. B : AType
3. P : x:AB(x)Prop
4. x:A. y:B(x). y is the y:B(x). P(x,y)
f:(x:AB(x)). x:A. P(x,f(x))
3 steps

About:

IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html