Metamath Proof Explorer


Theorem funresd

Description: A restriction of a function is a function. (Contributed by Glauco Siliprandi, 2-Jan-2022)

Ref Expression
Hypothesis funresd.1 φFunF
Assertion funresd φFunFA

Proof

Step Hyp Ref Expression
1 funresd.1 φFunF
2 funres FunFFunFA
3 1 2 syl φFunFA