Metamath Proof Explorer


Theorem ofmresval

Description: Value of a restriction of the function operation map. (Contributed by NM, 20-Oct-2014)

Ref Expression
Hypotheses ofmresval.f
|- ( ph -> F e. A )
ofmresval.g
|- ( ph -> G e. B )
Assertion ofmresval
|- ( ph -> ( F ( oF R |` ( A X. B ) ) G ) = ( F oF R G ) )

Proof

Step Hyp Ref Expression
1 ofmresval.f
 |-  ( ph -> F e. A )
2 ofmresval.g
 |-  ( ph -> G e. B )
3 ovres
 |-  ( ( F e. A /\ G e. B ) -> ( F ( oF R |` ( A X. B ) ) G ) = ( F oF R G ) )
4 1 2 3 syl2anc
 |-  ( ph -> ( F ( oF R |` ( A X. B ) ) G ) = ( F oF R G ) )