Metamath Proof Explorer


Theorem eccnvepres3

Description: Condition for a restricted converse epsilon coset of a set to be the set itself. (Contributed by Peter Mazsa, 11-May-2021)

Ref Expression
Assertion eccnvepres3
|- ( B e. dom ( `' _E |` A ) -> [ B ] ( `' _E |` A ) = B )

Proof

Step Hyp Ref Expression
1 resdmres
 |-  ( `' _E |` dom ( `' _E |` A ) ) = ( `' _E |` A )
2 1 eceq2i
 |-  [ B ] ( `' _E |` dom ( `' _E |` A ) ) = [ B ] ( `' _E |` A )
3 eccnvepres2
 |-  ( B e. dom ( `' _E |` A ) -> [ B ] ( `' _E |` dom ( `' _E |` A ) ) = B )
4 2 3 eqtr3id
 |-  ( B e. dom ( `' _E |` A ) -> [ B ] ( `' _E |` A ) = B )