Metamath Proof Explorer


Theorem hlgrcl1

Description: Reverse closure for rays. (Contributed by Thierry Arnoux, 13-Jul-2026)

Ref Expression
Hypotheses ishlg.p
|- P = ( Base ` G )
ishlg.i
|- I = ( Itv ` G )
ishlg.k
|- K = ( hlG ` G )
ishlg2.g
|- ( ph -> G e. V )
ishlg2.1
|- ( ph -> C e. P )
hlgrcl1.1
|- ( ph -> A ( K ` C ) B )
Assertion hlgrcl1
|- ( ph -> A e. P )

Proof

Step Hyp Ref Expression
1 ishlg.p
 |-  P = ( Base ` G )
2 ishlg.i
 |-  I = ( Itv ` G )
3 ishlg.k
 |-  K = ( hlG ` G )
4 ishlg2.g
 |-  ( ph -> G e. V )
5 ishlg2.1
 |-  ( ph -> C e. P )
6 hlgrcl1.1
 |-  ( ph -> A ( K ` C ) B )
7 1 2 3 4 5 ishlg2
 |-  ( ph -> ( A ( K ` C ) B <-> ( ( A e. P /\ B e. P ) /\ ( A =/= C /\ B =/= C /\ ( A e. ( C I B ) \/ B e. ( C I A ) ) ) ) ) )
8 6 7 mpbid
 |-  ( ph -> ( ( A e. P /\ B e. P ) /\ ( A =/= C /\ B =/= C /\ ( A e. ( C I B ) \/ B e. ( C I A ) ) ) ) )
9 8 simplld
 |-  ( ph -> A e. P )