Metamath Proof Explorer


Theorem 0nonelalab

Description: Technical lemma for open interval. (Contributed by metakunt, 12-Aug-2024)

Ref Expression
Hypotheses 0nonelaleb.1 ⊢ φ → A ∈ ℝ
0nonelaleb.2 ⊢ φ → B ∈ ℝ
0nonelaleb.3 ⊢ φ → 0 < A
0nonelaleb.4 ⊢ φ → A ≤ B
0nonelalab.5 ⊢ φ → C ∈ A B
Assertion 0nonelalab ⊢ φ → 0 ≠ C

Proof

Step Hyp Ref Expression
1 0nonelaleb.1 ⊢ φ → A ∈ ℝ
2 0nonelaleb.2 ⊢ φ → B ∈ ℝ
3 0nonelaleb.3 ⊢ φ → 0 < A
4 0nonelaleb.4 ⊢ φ → A ≤ B
5 0nonelalab.5 ⊢ φ → C ∈ A B
6 0red ⊢ φ → 0 ∈ ℝ
7 elioore ⊢ C ∈ A B → C ∈ ℝ
8 5 7 syl ⊢ φ → C ∈ ℝ
9 1 rexrd ⊢ φ → A ∈ ℝ *
10 2 rexrd ⊢ φ → B ∈ ℝ *
11 elioo2 ⊢ A ∈ ℝ * ∧ B ∈ ℝ * → C ∈ A B ↔ C ∈ ℝ ∧ A < C ∧ C < B
12 9 10 11 syl2anc ⊢ φ → C ∈ A B ↔ C ∈ ℝ ∧ A < C ∧ C < B
13 5 12 mpbid ⊢ φ → C ∈ ℝ ∧ A < C ∧ C < B
14 13 simp2d ⊢ φ → A < C
15 6 1 8 3 14 lttrd ⊢ φ → 0 < C
16 6 15 ltned ⊢ φ → 0 ≠ C