Metamath Proof Explorer


Theorem sotrine

Description: Trichotomy law for strict orderings. (Contributed by Scott Fenton, 8-Dec-2021)

Ref Expression
Assertion sotrine
|- ( ( R Or A /\ ( B e. A /\ C e. A ) ) -> ( B =/= C <-> ( B R C \/ C R B ) ) )

Proof

Step Hyp Ref Expression
1 sotrieq
 |-  ( ( R Or A /\ ( B e. A /\ C e. A ) ) -> ( B = C <-> -. ( B R C \/ C R B ) ) )
2 1 bicomd
 |-  ( ( R Or A /\ ( B e. A /\ C e. A ) ) -> ( -. ( B R C \/ C R B ) <-> B = C ) )
3 2 necon1abid
 |-  ( ( R Or A /\ ( B e. A /\ C e. A ) ) -> ( B =/= C <-> ( B R C \/ C R B ) ) )