Metamath Proof Explorer


Theorem ovconst2

Description: The value of a constant operation. (Contributed by NM, 5-Nov-2006)

Ref Expression
Hypothesis oprvalconst2.1
|- C e. _V
Assertion ovconst2
|- ( ( R e. A /\ S e. B ) -> ( R ( ( A X. B ) X. { C } ) S ) = C )

Proof

Step Hyp Ref Expression
1 oprvalconst2.1
 |-  C e. _V
2 df-ov
 |-  ( R ( ( A X. B ) X. { C } ) S ) = ( ( ( A X. B ) X. { C } ) ` <. R , S >. )
3 opelxpi
 |-  ( ( R e. A /\ S e. B ) -> <. R , S >. e. ( A X. B ) )
4 1 fvconst2
 |-  ( <. R , S >. e. ( A X. B ) -> ( ( ( A X. B ) X. { C } ) ` <. R , S >. ) = C )
5 3 4 syl
 |-  ( ( R e. A /\ S e. B ) -> ( ( ( A X. B ) X. { C } ) ` <. R , S >. ) = C )
6 2 5 eqtrid
 |-  ( ( R e. A /\ S e. B ) -> ( R ( ( A X. B ) X. { C } ) S ) = C )