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| Mirrors > Home > ILE Home > Th. List > ax-pre-apti | GIF version | ||
| Description: Apartness of reals is tight. Axiom for real and complex numbers, justified by Theorem axpre-apti 7952. (Contributed by Jim Kingdon, 29-Jan-2020.) | 
| Ref | Expression | 
|---|---|
| ax-pre-apti | ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ ¬ (𝐴 <ℝ 𝐵 ∨ 𝐵 <ℝ 𝐴)) → 𝐴 = 𝐵) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | cA | . . . 4 class 𝐴 | |
| 2 | cr 7878 | . . . 4 class ℝ | |
| 3 | 1, 2 | wcel 2167 | . . 3 wff 𝐴 ∈ ℝ | 
| 4 | cB | . . . 4 class 𝐵 | |
| 5 | 4, 2 | wcel 2167 | . . 3 wff 𝐵 ∈ ℝ | 
| 6 | cltrr 7883 | . . . . . 6 class <ℝ | |
| 7 | 1, 4, 6 | wbr 4033 | . . . . 5 wff 𝐴 <ℝ 𝐵 | 
| 8 | 4, 1, 6 | wbr 4033 | . . . . 5 wff 𝐵 <ℝ 𝐴 | 
| 9 | 7, 8 | wo 709 | . . . 4 wff (𝐴 <ℝ 𝐵 ∨ 𝐵 <ℝ 𝐴) | 
| 10 | 9 | wn 3 | . . 3 wff ¬ (𝐴 <ℝ 𝐵 ∨ 𝐵 <ℝ 𝐴) | 
| 11 | 3, 5, 10 | w3a 980 | . 2 wff (𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ ¬ (𝐴 <ℝ 𝐵 ∨ 𝐵 <ℝ 𝐴)) | 
| 12 | 1, 4 | wceq 1364 | . 2 wff 𝐴 = 𝐵 | 
| 13 | 11, 12 | wi 4 | 1 wff ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ ¬ (𝐴 <ℝ 𝐵 ∨ 𝐵 <ℝ 𝐴)) → 𝐴 = 𝐵) | 
| Colors of variables: wff set class | 
| This axiom is referenced by: axapti 8097 | 
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