Metamath Proof Explorer


Theorem petincnvepres2

Description: A partition-equivalence theorem with intersection and general R . (Contributed by Peter Mazsa, 31-Dec-2021)

Ref Expression
Assertion petincnvepres2
|- ( ( Disj ( R i^i ( `' _E |` A ) ) /\ ( dom ( R i^i ( `' _E |` A ) ) /. ( R i^i ( `' _E |` A ) ) ) = A ) <-> ( EqvRel ,~ ( R i^i ( `' _E |` A ) ) /\ ( dom ,~ ( R i^i ( `' _E |` A ) ) /. ,~ ( R i^i ( `' _E |` A ) ) ) = A ) )

Proof

Step Hyp Ref Expression
1 eqvrelqseqdisj4
 |-  ( ( EqvRel ,~ ( R i^i ( `' _E |` A ) ) /\ ( dom ,~ ( R i^i ( `' _E |` A ) ) /. ,~ ( R i^i ( `' _E |` A ) ) ) = A ) -> Disj ( R i^i ( `' _E |` A ) ) )
2 1 petlem
 |-  ( ( Disj ( R i^i ( `' _E |` A ) ) /\ ( dom ( R i^i ( `' _E |` A ) ) /. ( R i^i ( `' _E |` A ) ) ) = A ) <-> ( EqvRel ,~ ( R i^i ( `' _E |` A ) ) /\ ( dom ,~ ( R i^i ( `' _E |` A ) ) /. ,~ ( R i^i ( `' _E |` A ) ) ) = A ) )