Metamath Proof Explorer


Definition df-btwn

Description: Define the Euclidean betweenness predicate. For details, see brbtwn . (Contributed by Scott Fenton, 3-Jun-2013)

Ref Expression
Assertion df-btwn Btwn = ◡ { ⟨ ⟨ 𝑥 , 𝑧 ⟩ , 𝑦 ⟩ ∣ ∃ 𝑛 ∈ ℕ ( ( 𝑥 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑧 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑦 ∈ ( 𝔼 ‘ 𝑛 ) ) ∧ ∃ 𝑡 ∈ ( 0 [,] 1 ) ∀ 𝑖 ∈ ( 1 ... 𝑛 ) ( 𝑦 ‘ 𝑖 ) = ( ( ( 1 − 𝑡 ) · ( 𝑥 ‘ 𝑖 ) ) + ( 𝑡 · ( 𝑧 ‘ 𝑖 ) ) ) ) }

Detailed syntax breakdown

Step Hyp Ref Expression
0 cbtwn ⊢ Btwn
1 vx ⊢ 𝑥
2 vz ⊢ 𝑧
3 vy ⊢ 𝑦
4 vn ⊢ 𝑛
5 cn ⊢ ℕ
6 1 cv ⊢ 𝑥
7 cee ⊢ 𝔼
8 4 cv ⊢ 𝑛
9 8 7 cfv ⊢ ( 𝔼 ‘ 𝑛 )
10 6 9 wcel ⊢ 𝑥 ∈ ( 𝔼 ‘ 𝑛 )
11 2 cv ⊢ 𝑧
12 11 9 wcel ⊢ 𝑧 ∈ ( 𝔼 ‘ 𝑛 )
13 3 cv ⊢ 𝑦
14 13 9 wcel ⊢ 𝑦 ∈ ( 𝔼 ‘ 𝑛 )
15 10 12 14 w3a ⊢ ( 𝑥 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑧 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑦 ∈ ( 𝔼 ‘ 𝑛 ) )
16 vt ⊢ 𝑡
17 cc0 ⊢ 0
18 cicc ⊢ [,]
19 c1 ⊢ 1
20 17 19 18 co ⊢ ( 0 [,] 1 )
21 vi ⊢ 𝑖
22 cfz ⊢ ...
23 19 8 22 co ⊢ ( 1 ... 𝑛 )
24 21 cv ⊢ 𝑖
25 24 13 cfv ⊢ ( 𝑦 ‘ 𝑖 )
26 cmin ⊢ −
27 16 cv ⊢ 𝑡
28 19 27 26 co ⊢ ( 1 − 𝑡 )
29 cmul ⊢ ·
30 24 6 cfv ⊢ ( 𝑥 ‘ 𝑖 )
31 28 30 29 co ⊢ ( ( 1 − 𝑡 ) · ( 𝑥 ‘ 𝑖 ) )
32 caddc ⊢ +
33 24 11 cfv ⊢ ( 𝑧 ‘ 𝑖 )
34 27 33 29 co ⊢ ( 𝑡 · ( 𝑧 ‘ 𝑖 ) )
35 31 34 32 co ⊢ ( ( ( 1 − 𝑡 ) · ( 𝑥 ‘ 𝑖 ) ) + ( 𝑡 · ( 𝑧 ‘ 𝑖 ) ) )
36 25 35 wceq ⊢ ( 𝑦 ‘ 𝑖 ) = ( ( ( 1 − 𝑡 ) · ( 𝑥 ‘ 𝑖 ) ) + ( 𝑡 · ( 𝑧 ‘ 𝑖 ) ) )
37 36 21 23 wral ⊢ ∀ 𝑖 ∈ ( 1 ... 𝑛 ) ( 𝑦 ‘ 𝑖 ) = ( ( ( 1 − 𝑡 ) · ( 𝑥 ‘ 𝑖 ) ) + ( 𝑡 · ( 𝑧 ‘ 𝑖 ) ) )
38 37 16 20 wrex ⊢ ∃ 𝑡 ∈ ( 0 [,] 1 ) ∀ 𝑖 ∈ ( 1 ... 𝑛 ) ( 𝑦 ‘ 𝑖 ) = ( ( ( 1 − 𝑡 ) · ( 𝑥 ‘ 𝑖 ) ) + ( 𝑡 · ( 𝑧 ‘ 𝑖 ) ) )
39 15 38 wa ⊢ ( ( 𝑥 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑧 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑦 ∈ ( 𝔼 ‘ 𝑛 ) ) ∧ ∃ 𝑡 ∈ ( 0 [,] 1 ) ∀ 𝑖 ∈ ( 1 ... 𝑛 ) ( 𝑦 ‘ 𝑖 ) = ( ( ( 1 − 𝑡 ) · ( 𝑥 ‘ 𝑖 ) ) + ( 𝑡 · ( 𝑧 ‘ 𝑖 ) ) ) )
40 39 4 5 wrex ⊢ ∃ 𝑛 ∈ ℕ ( ( 𝑥 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑧 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑦 ∈ ( 𝔼 ‘ 𝑛 ) ) ∧ ∃ 𝑡 ∈ ( 0 [,] 1 ) ∀ 𝑖 ∈ ( 1 ... 𝑛 ) ( 𝑦 ‘ 𝑖 ) = ( ( ( 1 − 𝑡 ) · ( 𝑥 ‘ 𝑖 ) ) + ( 𝑡 · ( 𝑧 ‘ 𝑖 ) ) ) )
41 40 1 2 3 coprab ⊢ { ⟨ ⟨ 𝑥 , 𝑧 ⟩ , 𝑦 ⟩ ∣ ∃ 𝑛 ∈ ℕ ( ( 𝑥 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑧 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑦 ∈ ( 𝔼 ‘ 𝑛 ) ) ∧ ∃ 𝑡 ∈ ( 0 [,] 1 ) ∀ 𝑖 ∈ ( 1 ... 𝑛 ) ( 𝑦 ‘ 𝑖 ) = ( ( ( 1 − 𝑡 ) · ( 𝑥 ‘ 𝑖 ) ) + ( 𝑡 · ( 𝑧 ‘ 𝑖 ) ) ) ) }
42 41 ccnv ⊢ ◡ { ⟨ ⟨ 𝑥 , 𝑧 ⟩ , 𝑦 ⟩ ∣ ∃ 𝑛 ∈ ℕ ( ( 𝑥 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑧 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑦 ∈ ( 𝔼 ‘ 𝑛 ) ) ∧ ∃ 𝑡 ∈ ( 0 [,] 1 ) ∀ 𝑖 ∈ ( 1 ... 𝑛 ) ( 𝑦 ‘ 𝑖 ) = ( ( ( 1 − 𝑡 ) · ( 𝑥 ‘ 𝑖 ) ) + ( 𝑡 · ( 𝑧 ‘ 𝑖 ) ) ) ) }
43 0 42 wceq ⊢ Btwn = ◡ { ⟨ ⟨ 𝑥 , 𝑧 ⟩ , 𝑦 ⟩ ∣ ∃ 𝑛 ∈ ℕ ( ( 𝑥 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑧 ∈ ( 𝔼 ‘ 𝑛 ) ∧ 𝑦 ∈ ( 𝔼 ‘ 𝑛 ) ) ∧ ∃ 𝑡 ∈ ( 0 [,] 1 ) ∀ 𝑖 ∈ ( 1 ... 𝑛 ) ( 𝑦 ‘ 𝑖 ) = ( ( ( 1 − 𝑡 ) · ( 𝑥 ‘ 𝑖 ) ) + ( 𝑡 · ( 𝑧 ‘ 𝑖 ) ) ) ) }