Metamath Proof Explorer


Theorem dmxrncnvepres

Description: Domain of the range product with restricted converse epsilon relation. (Contributed by Peter Mazsa, 23-Nov-2025)

Ref Expression
Assertion dmxrncnvepres
|- dom ( R |X. ( `' _E |` A ) ) = ( dom ( R |` A ) \ { (/) } )

Proof

Step Hyp Ref Expression
1 xrnres
 |-  ( ( R |X. `' _E ) |` A ) = ( ( R |` A ) |X. `' _E )
2 xrnres2
 |-  ( ( R |X. `' _E ) |` A ) = ( R |X. ( `' _E |` A ) )
3 1 2 eqtr3i
 |-  ( ( R |` A ) |X. `' _E ) = ( R |X. ( `' _E |` A ) )
4 3 dmeqi
 |-  dom ( ( R |` A ) |X. `' _E ) = dom ( R |X. ( `' _E |` A ) )
5 dmxrncnvep
 |-  dom ( ( R |` A ) |X. `' _E ) = ( dom ( R |` A ) \ { (/) } )
6 4 5 eqtr3i
 |-  dom ( R |X. ( `' _E |` A ) ) = ( dom ( R |` A ) \ { (/) } )