Metamath Proof Explorer


Theorem dfantisymrel4

Description: Alternate definition of the antisymmetric relation predicate. (Contributed by Peter Mazsa, 24-Jun-2024)

Ref Expression
Assertion dfantisymrel4
|- ( AntisymRel R <-> ( ( R i^i `' R ) C_ _I /\ Rel R ) )

Proof

Step Hyp Ref Expression
1 df-antisymrel
 |-  ( AntisymRel R <-> ( CnvRefRel ( R i^i `' R ) /\ Rel R ) )
2 relcnv
 |-  Rel `' R
3 relin2
 |-  ( Rel `' R -> Rel ( R i^i `' R ) )
4 2 3 ax-mp
 |-  Rel ( R i^i `' R )
5 dfcnvrefrel4
 |-  ( CnvRefRel ( R i^i `' R ) <-> ( ( R i^i `' R ) C_ _I /\ Rel ( R i^i `' R ) ) )
6 4 5 mpbiran2
 |-  ( CnvRefRel ( R i^i `' R ) <-> ( R i^i `' R ) C_ _I )
7 1 6 bianbi
 |-  ( AntisymRel R <-> ( ( R i^i `' R ) C_ _I /\ Rel R ) )