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 ⊢ ( 𝜑 → 𝐺 ∈ 𝑉 )
ishlg2.1 ⊢ ( 𝜑 → 𝐶 ∈ 𝑃 )
hlgrcl1.1 ⊢ ( 𝜑 → 𝐴 ( 𝐾 ‘ 𝐶 ) 𝐵 )
Assertion hlgrcl1 ( 𝜑 → 𝐴 ∈ 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 ⊢ ( 𝜑 → 𝐺 ∈ 𝑉 )
5 ishlg2.1 ⊢ ( 𝜑 → 𝐶 ∈ 𝑃 )
6 hlgrcl1.1 ⊢ ( 𝜑 → 𝐴 ( 𝐾 ‘ 𝐶 ) 𝐵 )
7 1 2 3 4 5 ishlg2 ⊢ ( 𝜑 → ( 𝐴 ( 𝐾 ‘ 𝐶 ) 𝐵 ↔ ( ( 𝐴 ∈ 𝑃 ∧ 𝐵 ∈ 𝑃 ) ∧ ( 𝐴 ≠ 𝐶 ∧ 𝐵 ≠ 𝐶 ∧ ( 𝐴 ∈ ( 𝐶 𝐼 𝐵 ) ∨ 𝐵 ∈ ( 𝐶 𝐼 𝐴 ) ) ) ) ) )
8 6 7 mpbid ⊢ ( 𝜑 → ( ( 𝐴 ∈ 𝑃 ∧ 𝐵 ∈ 𝑃 ) ∧ ( 𝐴 ≠ 𝐶 ∧ 𝐵 ≠ 𝐶 ∧ ( 𝐴 ∈ ( 𝐶 𝐼 𝐵 ) ∨ 𝐵 ∈ ( 𝐶 𝐼 𝐴 ) ) ) ) )
9 8 simplld ⊢ ( 𝜑 → 𝐴 ∈ 𝑃 )