Metamath Proof Explorer


Theorem ovresd

Description: Lemma for converting metric theorems to metric space theorems. (Contributed by Mario Carneiro, 2-Oct-2015)

Ref Expression
Hypotheses ovresd.1 φ A X
ovresd.2 φ B X
Assertion ovresd φ A D X × X B = A D B

Proof

Step Hyp Ref Expression
1 ovresd.1 φ A X
2 ovresd.2 φ B X
3 ovres A X B X A D X × X B = A D B
4 1 2 3 syl2anc φ A D X × X B = A D B