Metamath Proof Explorer


Theorem elmapssresd

Description: A restricted mapping is a mapping. EDITORIAL: Could be used to shorten elpm2r with some reordering involving mapsspm . (Contributed by SN, 11-Mar-2025)

Ref Expression
Hypotheses elmapssresd.1 φ A B C
elmapssresd.2 φ D C
Assertion elmapssresd φ A D B D

Proof

Step Hyp Ref Expression
1 elmapssresd.1 φ A B C
2 elmapssresd.2 φ D C
3 elmapssres A B C D C A D B D
4 1 2 3 syl2anc φ A D B D