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 ) |
| 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 ) |