Metamath Proof Explorer


Theorem pet2

Description: Partition-Equivalence Theorem, with general R . This theorem (together with pet and pets ) is the main result of my investigation into set theory, see the comment of pet . (Contributed by Peter Mazsa, 24-May-2021) (Revised by Peter Mazsa, 23-Sep-2021)

Ref Expression
Assertion pet2
|- ( ( Disj ( R |X. ( `' _E |` A ) ) /\ ( dom ( R |X. ( `' _E |` A ) ) /. ( R |X. ( `' _E |` A ) ) ) = A ) <-> ( EqvRel ,~ ( R |X. ( `' _E |` A ) ) /\ ( dom ,~ ( R |X. ( `' _E |` A ) ) /. ,~ ( R |X. ( `' _E |` A ) ) ) = A ) )

Proof

Step Hyp Ref Expression
1 eqvrelqseqdisj5
 |-  ( ( EqvRel ,~ ( R |X. ( `' _E |` A ) ) /\ ( dom ,~ ( R |X. ( `' _E |` A ) ) /. ,~ ( R |X. ( `' _E |` A ) ) ) = A ) -> Disj ( R |X. ( `' _E |` A ) ) )
2 1 petlem
 |-  ( ( Disj ( R |X. ( `' _E |` A ) ) /\ ( dom ( R |X. ( `' _E |` A ) ) /. ( R |X. ( `' _E |` A ) ) ) = A ) <-> ( EqvRel ,~ ( R |X. ( `' _E |` A ) ) /\ ( dom ,~ ( R |X. ( `' _E |` A ) ) /. ,~ ( R |X. ( `' _E |` A ) ) ) = A ) )