Metamath Proof Explorer


Theorem trinxp

Description: The relation induced by a transitive relation on a part of its field is transitive. (Taking the intersection of a relation with a Cartesian square is a way to restrict it to a subset of its field.) (Contributed by FL, 31-Jul-2009)

Ref Expression
Assertion trinxp
|- ( ( R o. R ) C_ R -> ( ( R i^i ( A X. A ) ) o. ( R i^i ( A X. A ) ) ) C_ ( R i^i ( A X. A ) ) )

Proof

Step Hyp Ref Expression
1 xpidtr
 |-  ( ( A X. A ) o. ( A X. A ) ) C_ ( A X. A )
2 trin2
 |-  ( ( ( R o. R ) C_ R /\ ( ( A X. A ) o. ( A X. A ) ) C_ ( A X. A ) ) -> ( ( R i^i ( A X. A ) ) o. ( R i^i ( A X. A ) ) ) C_ ( R i^i ( A X. A ) ) )
3 1 2 mpan2
 |-  ( ( R o. R ) C_ R -> ( ( R i^i ( A X. A ) ) o. ( R i^i ( A X. A ) ) ) C_ ( R i^i ( A X. A ) ) )