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Metamath Proof Explorer


Theorem relcoels

Description: Coelements on A is a relation. (Contributed by Peter Mazsa, 5-Oct-2021)

Ref Expression
Assertion relcoels Rel A

Proof

Step Hyp Ref Expression
1 relcoss Rel E -1 A
2 df-coels A = E -1 A
3 2 releqi Rel A Rel E -1 A
4 1 3 mpbir Rel A