Metamath Proof Explorer


Theorem petxrnidres

Description: A class is a partition by a range Cartesian product with the identity class restricted to it if and only if the cosets by the range Cartesian product are in equivalence relation on it. Cf. br1cossxrnidres , disjALTVxrnidres and eqvrel1cossxrnidres . (Contributed by Peter Mazsa, 31-Dec-2021)

Ref Expression
Assertion petxrnidres Could not format assertion : No typesetting found for |- ( ( R |X. ( _I |` A ) ) Part A <-> ,~ ( R |X. ( _I |` A ) ) ErALTV A ) with typecode |-

Proof

Step Hyp Ref Expression
1 petxrnidres2 Disj R I A dom R I A / R I A = A EqvRel R I A dom R I A / R I A = A
2 dfpart2 Could not format ( ( R |X. ( _I |` A ) ) Part A <-> ( Disj ( R |X. ( _I |` A ) ) /\ ( dom ( R |X. ( _I |` A ) ) /. ( R |X. ( _I |` A ) ) ) = A ) ) : No typesetting found for |- ( ( R |X. ( _I |` A ) ) Part A <-> ( Disj ( R |X. ( _I |` A ) ) /\ ( dom ( R |X. ( _I |` A ) ) /. ( R |X. ( _I |` A ) ) ) = A ) ) with typecode |-
3 dferALTV2 R I A ErALTV A EqvRel R I A dom R I A / R I A = A
4 1 2 3 3bitr4i Could not format ( ( R |X. ( _I |` A ) ) Part A <-> ,~ ( R |X. ( _I |` A ) ) ErALTV A ) : No typesetting found for |- ( ( R |X. ( _I |` A ) ) Part A <-> ,~ ( R |X. ( _I |` A ) ) ErALTV A ) with typecode |-