Metamath Proof Explorer


Theorem nhpmirhp

Description: If a point Z is on the plane defined by a line A and a point Y , but not on the same half-plane as Y , then its mirror point ( MZ ) by a point X on A is on the same half-plane as Y . (Contributed by Thierry Arnoux, 5-Jul-2026)

Ref Expression
Hypotheses nhpmirhp.p 𝑃 = ( Base ‘ 𝐺 )
nhpmirhp.l 𝐿 = ( LineG ‘ 𝐺 )
nhpmirhp.s 𝑆 = ( pInvG ‘ 𝐺 )
nhpmirhp.e 𝐸 = ( hlG ‘ 𝐺 )
nhpmirhp.m 𝑀 = ( 𝑆𝑋 )
nhpmirhp.g ( 𝜑𝐺 ∈ TarskiG )
nhpmirhp.a ( 𝜑𝐴 ∈ ran 𝐿 )
nhpmirhp.x ( 𝜑𝑋𝐴 )
nhpmirhp.y ( 𝜑𝑌 ∈ ( 𝑃𝐴 ) )
nhpmirhp.z ( 𝜑𝑍 ∈ ( ( 𝐴 𝐸 𝑌 ) ∖ 𝐴 ) )
nhpmirhp.1 ( 𝜑 → ¬ 𝑌 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑍 )
Assertion nhpmirhp ( 𝜑𝑌 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) ( 𝑀𝑍 ) )

Proof

Step Hyp Ref Expression
1 nhpmirhp.p 𝑃 = ( Base ‘ 𝐺 )
2 nhpmirhp.l 𝐿 = ( LineG ‘ 𝐺 )
3 nhpmirhp.s 𝑆 = ( pInvG ‘ 𝐺 )
4 nhpmirhp.e 𝐸 = ( hlG ‘ 𝐺 )
5 nhpmirhp.m 𝑀 = ( 𝑆𝑋 )
6 nhpmirhp.g ( 𝜑𝐺 ∈ TarskiG )
7 nhpmirhp.a ( 𝜑𝐴 ∈ ran 𝐿 )
8 nhpmirhp.x ( 𝜑𝑋𝐴 )
9 nhpmirhp.y ( 𝜑𝑌 ∈ ( 𝑃𝐴 ) )
10 nhpmirhp.z ( 𝜑𝑍 ∈ ( ( 𝐴 𝐸 𝑌 ) ∖ 𝐴 ) )
11 nhpmirhp.1 ( 𝜑 → ¬ 𝑌 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑍 )
12 eqid ( dist ‘ 𝐺 ) = ( dist ‘ 𝐺 )
13 eqid ( Itv ‘ 𝐺 ) = ( Itv ‘ 𝐺 )
14 eleq1w ( 𝑥 = 𝑧 → ( 𝑥 ∈ ( 𝑃𝐴 ) ↔ 𝑧 ∈ ( 𝑃𝐴 ) ) )
15 eleq1w ( 𝑦 = 𝑤 → ( 𝑦 ∈ ( 𝑃𝐴 ) ↔ 𝑤 ∈ ( 𝑃𝐴 ) ) )
16 14 15 bi2anan9 ( ( 𝑥 = 𝑧𝑦 = 𝑤 ) → ( ( 𝑥 ∈ ( 𝑃𝐴 ) ∧ 𝑦 ∈ ( 𝑃𝐴 ) ) ↔ ( 𝑧 ∈ ( 𝑃𝐴 ) ∧ 𝑤 ∈ ( 𝑃𝐴 ) ) ) )
17 oveq12 ( ( 𝑥 = 𝑧𝑦 = 𝑤 ) → ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) = ( 𝑧 ( Itv ‘ 𝐺 ) 𝑤 ) )
18 17 eleq2d ( ( 𝑥 = 𝑧𝑦 = 𝑤 ) → ( 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ↔ 𝑠 ∈ ( 𝑧 ( Itv ‘ 𝐺 ) 𝑤 ) ) )
19 18 rexbidv ( ( 𝑥 = 𝑧𝑦 = 𝑤 ) → ( ∃ 𝑠𝐴 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ↔ ∃ 𝑠𝐴 𝑠 ∈ ( 𝑧 ( Itv ‘ 𝐺 ) 𝑤 ) ) )
20 eleq1w ( 𝑠 = 𝑡 → ( 𝑠 ∈ ( 𝑧 ( Itv ‘ 𝐺 ) 𝑤 ) ↔ 𝑡 ∈ ( 𝑧 ( Itv ‘ 𝐺 ) 𝑤 ) ) )
21 20 cbvrexvw ( ∃ 𝑠𝐴 𝑠 ∈ ( 𝑧 ( Itv ‘ 𝐺 ) 𝑤 ) ↔ ∃ 𝑡𝐴 𝑡 ∈ ( 𝑧 ( Itv ‘ 𝐺 ) 𝑤 ) )
22 19 21 bitrdi ( ( 𝑥 = 𝑧𝑦 = 𝑤 ) → ( ∃ 𝑠𝐴 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ↔ ∃ 𝑡𝐴 𝑡 ∈ ( 𝑧 ( Itv ‘ 𝐺 ) 𝑤 ) ) )
23 16 22 anbi12d ( ( 𝑥 = 𝑧𝑦 = 𝑤 ) → ( ( ( 𝑥 ∈ ( 𝑃𝐴 ) ∧ 𝑦 ∈ ( 𝑃𝐴 ) ) ∧ ∃ 𝑠𝐴 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ) ↔ ( ( 𝑧 ∈ ( 𝑃𝐴 ) ∧ 𝑤 ∈ ( 𝑃𝐴 ) ) ∧ ∃ 𝑡𝐴 𝑡 ∈ ( 𝑧 ( Itv ‘ 𝐺 ) 𝑤 ) ) ) )
24 23 cbvopabv { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ ( 𝑃𝐴 ) ∧ 𝑦 ∈ ( 𝑃𝐴 ) ) ∧ ∃ 𝑠𝐴 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ) } = { ⟨ 𝑧 , 𝑤 ⟩ ∣ ( ( 𝑧 ∈ ( 𝑃𝐴 ) ∧ 𝑤 ∈ ( 𝑃𝐴 ) ) ∧ ∃ 𝑡𝐴 𝑡 ∈ ( 𝑧 ( Itv ‘ 𝐺 ) 𝑤 ) ) }
25 10 eldifad ( 𝜑𝑍 ∈ ( 𝐴 𝐸 𝑌 ) )
26 1 13 2 4 6 7 9 25 plngssp ( 𝜑𝑍𝑃 )
27 1 2 13 6 7 8 tglnpt ( 𝜑𝑋𝑃 )
28 1 12 13 2 3 6 27 5 26 mircl ( 𝜑 → ( 𝑀𝑍 ) ∈ 𝑃 )
29 10 eldifbd ( 𝜑 → ¬ 𝑍𝐴 )
30 26 29 eldifd ( 𝜑𝑍 ∈ ( 𝑃𝐴 ) )
31 1 13 3 5 24 6 7 8 30 2 oppmir ( 𝜑𝑍 { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ ( 𝑃𝐴 ) ∧ 𝑦 ∈ ( 𝑃𝐴 ) ) ∧ ∃ 𝑠𝐴 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ) } ( 𝑀𝑍 ) )
32 1 12 13 24 2 7 6 26 28 31 oppcom ( 𝜑 → ( 𝑀𝑍 ) { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ ( 𝑃𝐴 ) ∧ 𝑦 ∈ ( 𝑃𝐴 ) ) ∧ ∃ 𝑠𝐴 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ) } 𝑍 )
33 9 eldifad ( 𝜑𝑌𝑃 )
34 6 adantr ( ( 𝜑𝑍 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑌 ) → 𝐺 ∈ TarskiG )
35 7 adantr ( ( 𝜑𝑍 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑌 ) → 𝐴 ∈ ran 𝐿 )
36 26 adantr ( ( 𝜑𝑍 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑌 ) → 𝑍𝑃 )
37 33 adantr ( ( 𝜑𝑍 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑌 ) → 𝑌𝑃 )
38 simpr ( ( 𝜑𝑍 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑌 ) → 𝑍 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑌 )
39 1 13 2 34 35 36 24 37 38 hpgcom ( ( 𝜑𝑍 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑌 ) → 𝑌 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑍 )
40 11 39 mtand ( 𝜑 → ¬ 𝑍 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑌 )
41 1 13 2 4 6 7 9 24 26 elplng ( 𝜑 → ( 𝑍 ∈ ( 𝐴 𝐸 𝑌 ) ↔ ( 𝑍𝐴𝑍 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑌𝑍 { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ ( 𝑃𝐴 ) ∧ 𝑦 ∈ ( 𝑃𝐴 ) ) ∧ ∃ 𝑠𝐴 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ) } 𝑌 ) ) )
42 25 41 mpbid ( 𝜑 → ( 𝑍𝐴𝑍 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) 𝑌𝑍 { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ ( 𝑃𝐴 ) ∧ 𝑦 ∈ ( 𝑃𝐴 ) ) ∧ ∃ 𝑠𝐴 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ) } 𝑌 ) )
43 29 40 42 ecase33d ( 𝜑𝑍 { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ ( 𝑃𝐴 ) ∧ 𝑦 ∈ ( 𝑃𝐴 ) ) ∧ ∃ 𝑠𝐴 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ) } 𝑌 )
44 1 12 13 24 2 7 6 26 33 43 oppcom ( 𝜑𝑌 { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ ( 𝑃𝐴 ) ∧ 𝑦 ∈ ( 𝑃𝐴 ) ) ∧ ∃ 𝑠𝐴 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ) } 𝑍 )
45 1 13 2 24 6 7 33 28 26 44 lnopp2hpgb ( 𝜑 → ( ( 𝑀𝑍 ) { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ ( 𝑃𝐴 ) ∧ 𝑦 ∈ ( 𝑃𝐴 ) ) ∧ ∃ 𝑠𝐴 𝑠 ∈ ( 𝑥 ( Itv ‘ 𝐺 ) 𝑦 ) ) } 𝑍𝑌 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) ( 𝑀𝑍 ) ) )
46 32 45 mpbid ( 𝜑𝑌 ( ( hpG ‘ 𝐺 ) ‘ 𝐴 ) ( 𝑀𝑍 ) )