Metamath Proof Explorer


Theorem refrelcoss2

Description: The class of cosets by R is reflexive, see dfrefrel2 . (Contributed by Peter Mazsa, 30-Jul-2019)

Ref Expression
Assertion refrelcoss2
|- ( ( _I i^i ( dom ,~ R X. ran ,~ R ) ) C_ ,~ R /\ Rel ,~ R )

Proof

Step Hyp Ref Expression
1 refrelcoss3
 |-  ( A. x e. dom ,~ R A. y e. ran ,~ R ( x = y -> x ,~ R y ) /\ Rel ,~ R )
2 idinxpss
 |-  ( ( _I i^i ( dom ,~ R X. ran ,~ R ) ) C_ ,~ R <-> A. x e. dom ,~ R A. y e. ran ,~ R ( x = y -> x ,~ R y ) )
3 2 anbi1i
 |-  ( ( ( _I i^i ( dom ,~ R X. ran ,~ R ) ) C_ ,~ R /\ Rel ,~ R ) <-> ( A. x e. dom ,~ R A. y e. ran ,~ R ( x = y -> x ,~ R y ) /\ Rel ,~ R ) )
4 1 3 mpbir
 |-  ( ( _I i^i ( dom ,~ R X. ran ,~ R ) ) C_ ,~ R /\ Rel ,~ R )