Metamath Proof Explorer


Theorem partim

Description: Partition implies equivalence relation by the cosets of the relation on its natural domain, cf. partim2 . (Contributed by Peter Mazsa, 17-Sep-2021)

Ref Expression
Assertion partim
|- ( R Part A -> ,~ R ErALTV A )

Proof

Step Hyp Ref Expression
1 partim2
 |-  ( ( Disj R /\ ( dom R /. R ) = A ) -> ( EqvRel ,~ R /\ ( dom ,~ R /. ,~ R ) = A ) )
2 dfpart2
 |-  ( R Part A <-> ( Disj R /\ ( dom R /. R ) = A ) )
3 dferALTV2
 |-  ( ,~ R ErALTV A <-> ( EqvRel ,~ R /\ ( dom ,~ R /. ,~ R ) = A ) )
4 1 2 3 3imtr4i
 |-  ( R Part A -> ,~ R ErALTV A )