Metamath Proof Explorer

Theorem endofsegid

Description: If A , B , and C fall in order on a line, and A B and A C are congruent, then C = B . (Contributed by Scott Fenton, 7-Oct-2013)

Ref Expression
Assertion endofsegid ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ( 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ) → 𝐶 = 𝐵 ) )

Proof

Step Hyp Ref Expression
1 simpl ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → 𝑁 ∈ ℕ )
2 simpr1 ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) )
3 simpr3 ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) )
4 simpr2 ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) )
5 cgrcom ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ↔ ⟨ 𝐴 , 𝐵 ⟩ Cgr ⟨ 𝐴 , 𝐶 ⟩ ) )
6 1 2 3 2 4 5 syl122anc ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ↔ ⟨ 𝐴 , 𝐵 ⟩ Cgr ⟨ 𝐴 , 𝐶 ⟩ ) )
7 6 biimpd ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ → ⟨ 𝐴 , 𝐵 ⟩ Cgr ⟨ 𝐴 , 𝐶 ⟩ ) )
8 idd ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ → ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ) )
9 axcgrrflx ⊢ ( ( 𝑁 ∈ ℕ ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) → ⟨ 𝐵 , 𝐶 ⟩ Cgr ⟨ 𝐶 , 𝐵 ⟩ )
10 9 3adant3r1 ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ⟨ 𝐵 , 𝐶 ⟩ Cgr ⟨ 𝐶 , 𝐵 ⟩ )
11 10 a1d ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ → ⟨ 𝐵 , 𝐶 ⟩ Cgr ⟨ 𝐶 , 𝐵 ⟩ ) )
12 7 8 11 3jcad ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ → ( ⟨ 𝐴 , 𝐵 ⟩ Cgr ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ∧ ⟨ 𝐵 , 𝐶 ⟩ Cgr ⟨ 𝐶 , 𝐵 ⟩ ) ) )
13 3ancomb ⊢ ( ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ) ↔ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) )
14 brcgr3 ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ⟨ 𝐴 , ⟨ 𝐵 , 𝐶 ⟩ ⟩ Cgr3 ⟨ 𝐴 , ⟨ 𝐶 , 𝐵 ⟩ ⟩ ↔ ( ⟨ 𝐴 , 𝐵 ⟩ Cgr ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ∧ ⟨ 𝐵 , 𝐶 ⟩ Cgr ⟨ 𝐶 , 𝐵 ⟩ ) ) )
15 13 14 syl3an3br ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ⟨ 𝐴 , ⟨ 𝐵 , 𝐶 ⟩ ⟩ Cgr3 ⟨ 𝐴 , ⟨ 𝐶 , 𝐵 ⟩ ⟩ ↔ ( ⟨ 𝐴 , 𝐵 ⟩ Cgr ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ∧ ⟨ 𝐵 , 𝐶 ⟩ Cgr ⟨ 𝐶 , 𝐵 ⟩ ) ) )
16 15 3anidm23 ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ⟨ 𝐴 , ⟨ 𝐵 , 𝐶 ⟩ ⟩ Cgr3 ⟨ 𝐴 , ⟨ 𝐶 , 𝐵 ⟩ ⟩ ↔ ( ⟨ 𝐴 , 𝐵 ⟩ Cgr ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ∧ ⟨ 𝐵 , 𝐶 ⟩ Cgr ⟨ 𝐶 , 𝐵 ⟩ ) ) )
17 12 16 sylibrd ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ → ⟨ 𝐴 , ⟨ 𝐵 , 𝐶 ⟩ ⟩ Cgr3 ⟨ 𝐴 , ⟨ 𝐶 , 𝐵 ⟩ ⟩ ) )
18 btwnxfr ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ( 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , ⟨ 𝐵 , 𝐶 ⟩ ⟩ Cgr3 ⟨ 𝐴 , ⟨ 𝐶 , 𝐵 ⟩ ⟩ ) → 𝐶 Btwn ⟨ 𝐴 , 𝐵 ⟩ ) )
19 13 18 syl3an3br ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ( 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , ⟨ 𝐵 , 𝐶 ⟩ ⟩ Cgr3 ⟨ 𝐴 , ⟨ 𝐶 , 𝐵 ⟩ ⟩ ) → 𝐶 Btwn ⟨ 𝐴 , 𝐵 ⟩ ) )
20 19 3anidm23 ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ( 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , ⟨ 𝐵 , 𝐶 ⟩ ⟩ Cgr3 ⟨ 𝐴 , ⟨ 𝐶 , 𝐵 ⟩ ⟩ ) → 𝐶 Btwn ⟨ 𝐴 , 𝐵 ⟩ ) )
21 17 20 sylan2d ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ( 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ) → 𝐶 Btwn ⟨ 𝐴 , 𝐵 ⟩ ) )
22 simpl ⊢ ( ( 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ) → 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ )
23 22 a1i ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ( 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ) → 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ) )
24 21 23 jcad ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ( 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ) → ( 𝐶 Btwn ⟨ 𝐴 , 𝐵 ⟩ ∧ 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ) ) )
25 3anrot ⊢ ( ( 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ) ↔ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) )
26 btwnswapid2 ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ( 𝐶 Btwn ⟨ 𝐴 , 𝐵 ⟩ ∧ 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ) → 𝐶 = 𝐵 ) )
27 25 26 sylan2br ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ( 𝐶 Btwn ⟨ 𝐴 , 𝐵 ⟩ ∧ 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ) → 𝐶 = 𝐵 ) )
28 24 27 syld ⊢ ( ( 𝑁 ∈ ℕ ∧ ( 𝐴 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐵 ∈ ( 𝔼 ‘ 𝑁 ) ∧ 𝐶 ∈ ( 𝔼 ‘ 𝑁 ) ) ) → ( ( 𝐵 Btwn ⟨ 𝐴 , 𝐶 ⟩ ∧ ⟨ 𝐴 , 𝐶 ⟩ Cgr ⟨ 𝐴 , 𝐵 ⟩ ) → 𝐶 = 𝐵 ) )