Metamath Proof Explorer


Theorem brafn

Description: The bra function is a functional. (Contributed by NM, 23-May-2006) (Revised by Mario Carneiro, 16-Nov-2013) (New usage is discouraged.)

Ref Expression
Assertion brafn A bra A :

Proof

Step Hyp Ref Expression
1 brafval A bra A = x x ih A
2 hicl x A x ih A
3 2 ancoms A x x ih A
4 1 3 fmpt3d A bra A :