Metamath Proof Explorer


Theorem disjim

Description: The "Divide et Aequivalere" Theorem: every disjoint relation generates equivalent cosets by the relation: generalization of the former prter1 , cf. eldisjim . (Contributed by Peter Mazsa, 3-May-2019) (Revised by Peter Mazsa, 17-Sep-2021)

Ref Expression
Assertion disjim
|- ( Disj R -> EqvRel ,~ R )

Proof

Step Hyp Ref Expression
1 dfdisjALTV4
 |-  ( Disj R <-> ( A. y E* u u R y /\ Rel R ) )
2 1 simplbi
 |-  ( Disj R -> A. y E* u u R y )
3 trcoss
 |-  ( A. y E* u u R y -> A. x A. y A. z ( ( x ,~ R y /\ y ,~ R z ) -> x ,~ R z ) )
4 2 3 syl
 |-  ( Disj R -> A. x A. y A. z ( ( x ,~ R y /\ y ,~ R z ) -> x ,~ R z ) )
5 eqvrelcoss3
 |-  ( EqvRel ,~ R <-> A. x A. y A. z ( ( x ,~ R y /\ y ,~ R z ) -> x ,~ R z ) )
6 4 5 sylibr
 |-  ( Disj R -> EqvRel ,~ R )