Metamath Proof Explorer


Theorem cotr2

Description: Two ways of saying a relation is transitive. Special instance of cotr2g . (Contributed by RP, 22-Mar-2020)

Ref Expression
Hypotheses cotr2.a
|- dom R C_ A
cotr2.b
|- ( dom R i^i ran R ) C_ B
cotr2.c
|- ran R C_ C
Assertion cotr2
|- ( ( R o. R ) C_ R <-> A. x e. A A. y e. B A. z e. C ( ( x R y /\ y R z ) -> x R z ) )

Proof

Step Hyp Ref Expression
1 cotr2.a
 |-  dom R C_ A
2 cotr2.b
 |-  ( dom R i^i ran R ) C_ B
3 cotr2.c
 |-  ran R C_ C
4 incom
 |-  ( dom R i^i ran R ) = ( ran R i^i dom R )
5 4 2 eqsstrri
 |-  ( ran R i^i dom R ) C_ B
6 1 5 3 cotr2g
 |-  ( ( R o. R ) C_ R <-> A. x e. A A. y e. B A. z e. C ( ( x R y /\ y R z ) -> x R z ) )