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Description: Lemma for xrsupss . (Contributed by NM, 25-Oct-2005)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | xrsupsslem | ⊢ ( ( 𝐴 ⊆ ℝ* ∧ ( 𝐴 ⊆ ℝ ∨ +∞ ∈ 𝐴 ) ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | raleq | ⊢ ( 𝐴 = ∅ → ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ↔ ∀ 𝑦 ∈ ∅ ¬ 𝑥 < 𝑦 ) ) | |
| 2 | rexeq | ⊢ ( 𝐴 = ∅ → ( ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ↔ ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) | |
| 3 | 2 | imbi2d | ⊢ ( 𝐴 = ∅ → ( ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ↔ ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) ) |
| 4 | 3 | ralbidv | ⊢ ( 𝐴 = ∅ → ( ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ↔ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) ) |
| 5 | 1 4 | anbi12d | ⊢ ( 𝐴 = ∅ → ( ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ↔ ( ∀ 𝑦 ∈ ∅ ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) ) ) |
| 6 | 5 | rexbidv | ⊢ ( 𝐴 = ∅ → ( ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ↔ ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ ∅ ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) ) ) |
| 7 | sup3 | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ∧ ∃ 𝑥 ∈ ℝ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) → ∃ 𝑥 ∈ ℝ ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) | |
| 8 | rexr | ⊢ ( 𝑥 ∈ ℝ → 𝑥 ∈ ℝ* ) | |
| 9 | 8 | anim1i | ⊢ ( ( 𝑥 ∈ ℝ ∧ ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) → ( 𝑥 ∈ ℝ* ∧ ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 10 | 9 | reximi2 | ⊢ ( ∃ 𝑥 ∈ ℝ ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 11 | 7 10 | syl | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ∧ ∃ 𝑥 ∈ ℝ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 12 | elxr | ⊢ ( 𝑦 ∈ ℝ* ↔ ( 𝑦 ∈ ℝ ∨ 𝑦 = +∞ ∨ 𝑦 = -∞ ) ) | |
| 13 | simpr | ⊢ ( ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) ∧ ( 𝑦 ∈ ℝ → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) → ( 𝑦 ∈ ℝ → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) | |
| 14 | pnfnlt | ⊢ ( 𝑥 ∈ ℝ* → ¬ +∞ < 𝑥 ) | |
| 15 | 14 | adantr | ⊢ ( ( 𝑥 ∈ ℝ* ∧ 𝑦 = +∞ ) → ¬ +∞ < 𝑥 ) |
| 16 | breq1 | ⊢ ( 𝑦 = +∞ → ( 𝑦 < 𝑥 ↔ +∞ < 𝑥 ) ) | |
| 17 | 16 | notbid | ⊢ ( 𝑦 = +∞ → ( ¬ 𝑦 < 𝑥 ↔ ¬ +∞ < 𝑥 ) ) |
| 18 | 17 | adantl | ⊢ ( ( 𝑥 ∈ ℝ* ∧ 𝑦 = +∞ ) → ( ¬ 𝑦 < 𝑥 ↔ ¬ +∞ < 𝑥 ) ) |
| 19 | 15 18 | mpbird | ⊢ ( ( 𝑥 ∈ ℝ* ∧ 𝑦 = +∞ ) → ¬ 𝑦 < 𝑥 ) |
| 20 | 19 | pm2.21d | ⊢ ( ( 𝑥 ∈ ℝ* ∧ 𝑦 = +∞ ) → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) |
| 21 | 20 | ex | ⊢ ( 𝑥 ∈ ℝ* → ( 𝑦 = +∞ → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 22 | 21 | ad2antlr | ⊢ ( ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) ∧ ( 𝑦 ∈ ℝ → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) → ( 𝑦 = +∞ → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 23 | ssel | ⊢ ( 𝐴 ⊆ ℝ → ( 𝑧 ∈ 𝐴 → 𝑧 ∈ ℝ ) ) | |
| 24 | mnflt | ⊢ ( 𝑧 ∈ ℝ → -∞ < 𝑧 ) | |
| 25 | 23 24 | syl6 | ⊢ ( 𝐴 ⊆ ℝ → ( 𝑧 ∈ 𝐴 → -∞ < 𝑧 ) ) |
| 26 | 25 | ancld | ⊢ ( 𝐴 ⊆ ℝ → ( 𝑧 ∈ 𝐴 → ( 𝑧 ∈ 𝐴 ∧ -∞ < 𝑧 ) ) ) |
| 27 | 26 | eximdv | ⊢ ( 𝐴 ⊆ ℝ → ( ∃ 𝑧 𝑧 ∈ 𝐴 → ∃ 𝑧 ( 𝑧 ∈ 𝐴 ∧ -∞ < 𝑧 ) ) ) |
| 28 | n0 | ⊢ ( 𝐴 ≠ ∅ ↔ ∃ 𝑧 𝑧 ∈ 𝐴 ) | |
| 29 | df-rex | ⊢ ( ∃ 𝑧 ∈ 𝐴 -∞ < 𝑧 ↔ ∃ 𝑧 ( 𝑧 ∈ 𝐴 ∧ -∞ < 𝑧 ) ) | |
| 30 | 27 28 29 | 3imtr4g | ⊢ ( 𝐴 ⊆ ℝ → ( 𝐴 ≠ ∅ → ∃ 𝑧 ∈ 𝐴 -∞ < 𝑧 ) ) |
| 31 | 30 | imp | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) → ∃ 𝑧 ∈ 𝐴 -∞ < 𝑧 ) |
| 32 | 31 | a1d | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) → ( -∞ < 𝑥 → ∃ 𝑧 ∈ 𝐴 -∞ < 𝑧 ) ) |
| 33 | 32 | ad2antrr | ⊢ ( ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) ∧ 𝑦 = -∞ ) → ( -∞ < 𝑥 → ∃ 𝑧 ∈ 𝐴 -∞ < 𝑧 ) ) |
| 34 | breq1 | ⊢ ( 𝑦 = -∞ → ( 𝑦 < 𝑥 ↔ -∞ < 𝑥 ) ) | |
| 35 | breq1 | ⊢ ( 𝑦 = -∞ → ( 𝑦 < 𝑧 ↔ -∞ < 𝑧 ) ) | |
| 36 | 35 | rexbidv | ⊢ ( 𝑦 = -∞ → ( ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ↔ ∃ 𝑧 ∈ 𝐴 -∞ < 𝑧 ) ) |
| 37 | 34 36 | imbi12d | ⊢ ( 𝑦 = -∞ → ( ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ↔ ( -∞ < 𝑥 → ∃ 𝑧 ∈ 𝐴 -∞ < 𝑧 ) ) ) |
| 38 | 37 | adantl | ⊢ ( ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) ∧ 𝑦 = -∞ ) → ( ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ↔ ( -∞ < 𝑥 → ∃ 𝑧 ∈ 𝐴 -∞ < 𝑧 ) ) ) |
| 39 | 33 38 | mpbird | ⊢ ( ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) ∧ 𝑦 = -∞ ) → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) |
| 40 | 39 | ex | ⊢ ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) → ( 𝑦 = -∞ → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 41 | 40 | adantr | ⊢ ( ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) ∧ ( 𝑦 ∈ ℝ → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) → ( 𝑦 = -∞ → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 42 | 13 22 41 | 3jaod | ⊢ ( ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) ∧ ( 𝑦 ∈ ℝ → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) → ( ( 𝑦 ∈ ℝ ∨ 𝑦 = +∞ ∨ 𝑦 = -∞ ) → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 43 | 12 42 | biimtrid | ⊢ ( ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) ∧ ( 𝑦 ∈ ℝ → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) → ( 𝑦 ∈ ℝ* → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 44 | 43 | ex | ⊢ ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) → ( ( 𝑦 ∈ ℝ → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) → ( 𝑦 ∈ ℝ* → ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 45 | 44 | ralimdv2 | ⊢ ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) → ( ∀ 𝑦 ∈ ℝ ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) → ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 46 | 45 | anim2d | ⊢ ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ 𝑥 ∈ ℝ* ) → ( ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) → ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 47 | 46 | reximdva | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) → ( ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 48 | 47 | 3adant3 | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ∧ ∃ 𝑥 ∈ ℝ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) → ( ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 49 | 11 48 | mpd | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ∧ ∃ 𝑥 ∈ ℝ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 50 | 49 | 3expa | ⊢ ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ ∃ 𝑥 ∈ ℝ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 51 | ralnex | ⊢ ( ∀ 𝑥 ∈ ℝ ¬ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ↔ ¬ ∃ 𝑥 ∈ ℝ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) | |
| 52 | rexnal | ⊢ ( ∃ 𝑦 ∈ 𝐴 ¬ 𝑦 ≤ 𝑥 ↔ ¬ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) | |
| 53 | ssel2 | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝑦 ∈ 𝐴 ) → 𝑦 ∈ ℝ ) | |
| 54 | letric | ⊢ ( ( 𝑦 ∈ ℝ ∧ 𝑥 ∈ ℝ ) → ( 𝑦 ≤ 𝑥 ∨ 𝑥 ≤ 𝑦 ) ) | |
| 55 | 54 | ord | ⊢ ( ( 𝑦 ∈ ℝ ∧ 𝑥 ∈ ℝ ) → ( ¬ 𝑦 ≤ 𝑥 → 𝑥 ≤ 𝑦 ) ) |
| 56 | 53 55 | sylan | ⊢ ( ( ( 𝐴 ⊆ ℝ ∧ 𝑦 ∈ 𝐴 ) ∧ 𝑥 ∈ ℝ ) → ( ¬ 𝑦 ≤ 𝑥 → 𝑥 ≤ 𝑦 ) ) |
| 57 | 56 | an32s | ⊢ ( ( ( 𝐴 ⊆ ℝ ∧ 𝑥 ∈ ℝ ) ∧ 𝑦 ∈ 𝐴 ) → ( ¬ 𝑦 ≤ 𝑥 → 𝑥 ≤ 𝑦 ) ) |
| 58 | 57 | reximdva | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝑥 ∈ ℝ ) → ( ∃ 𝑦 ∈ 𝐴 ¬ 𝑦 ≤ 𝑥 → ∃ 𝑦 ∈ 𝐴 𝑥 ≤ 𝑦 ) ) |
| 59 | 52 58 | biimtrrid | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝑥 ∈ ℝ ) → ( ¬ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 → ∃ 𝑦 ∈ 𝐴 𝑥 ≤ 𝑦 ) ) |
| 60 | 59 | ralimdva | ⊢ ( 𝐴 ⊆ ℝ → ( ∀ 𝑥 ∈ ℝ ¬ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 → ∀ 𝑥 ∈ ℝ ∃ 𝑦 ∈ 𝐴 𝑥 ≤ 𝑦 ) ) |
| 61 | 60 | imp | ⊢ ( ( 𝐴 ⊆ ℝ ∧ ∀ 𝑥 ∈ ℝ ¬ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) → ∀ 𝑥 ∈ ℝ ∃ 𝑦 ∈ 𝐴 𝑥 ≤ 𝑦 ) |
| 62 | 51 61 | sylan2br | ⊢ ( ( 𝐴 ⊆ ℝ ∧ ¬ ∃ 𝑥 ∈ ℝ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) → ∀ 𝑥 ∈ ℝ ∃ 𝑦 ∈ 𝐴 𝑥 ≤ 𝑦 ) |
| 63 | breq2 | ⊢ ( 𝑦 = 𝑧 → ( 𝑥 ≤ 𝑦 ↔ 𝑥 ≤ 𝑧 ) ) | |
| 64 | 63 | cbvrexvw | ⊢ ( ∃ 𝑦 ∈ 𝐴 𝑥 ≤ 𝑦 ↔ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ) |
| 65 | 64 | ralbii | ⊢ ( ∀ 𝑥 ∈ ℝ ∃ 𝑦 ∈ 𝐴 𝑥 ≤ 𝑦 ↔ ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ) |
| 66 | 62 65 | sylib | ⊢ ( ( 𝐴 ⊆ ℝ ∧ ¬ ∃ 𝑥 ∈ ℝ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) → ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ) |
| 67 | pnfxr | ⊢ +∞ ∈ ℝ* | |
| 68 | ssel | ⊢ ( 𝐴 ⊆ ℝ → ( 𝑦 ∈ 𝐴 → 𝑦 ∈ ℝ ) ) | |
| 69 | rexr | ⊢ ( 𝑦 ∈ ℝ → 𝑦 ∈ ℝ* ) | |
| 70 | pnfnlt | ⊢ ( 𝑦 ∈ ℝ* → ¬ +∞ < 𝑦 ) | |
| 71 | 69 70 | syl | ⊢ ( 𝑦 ∈ ℝ → ¬ +∞ < 𝑦 ) |
| 72 | 68 71 | syl6 | ⊢ ( 𝐴 ⊆ ℝ → ( 𝑦 ∈ 𝐴 → ¬ +∞ < 𝑦 ) ) |
| 73 | 72 | ralrimiv | ⊢ ( 𝐴 ⊆ ℝ → ∀ 𝑦 ∈ 𝐴 ¬ +∞ < 𝑦 ) |
| 74 | 73 | adantr | ⊢ ( ( 𝐴 ⊆ ℝ ∧ ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ) → ∀ 𝑦 ∈ 𝐴 ¬ +∞ < 𝑦 ) |
| 75 | peano2re | ⊢ ( 𝑦 ∈ ℝ → ( 𝑦 + 1 ) ∈ ℝ ) | |
| 76 | breq1 | ⊢ ( 𝑥 = ( 𝑦 + 1 ) → ( 𝑥 ≤ 𝑧 ↔ ( 𝑦 + 1 ) ≤ 𝑧 ) ) | |
| 77 | 76 | rexbidv | ⊢ ( 𝑥 = ( 𝑦 + 1 ) → ( ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ↔ ∃ 𝑧 ∈ 𝐴 ( 𝑦 + 1 ) ≤ 𝑧 ) ) |
| 78 | 77 | rspcva | ⊢ ( ( ( 𝑦 + 1 ) ∈ ℝ ∧ ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ) → ∃ 𝑧 ∈ 𝐴 ( 𝑦 + 1 ) ≤ 𝑧 ) |
| 79 | 78 | adantrr | ⊢ ( ( ( 𝑦 + 1 ) ∈ ℝ ∧ ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ∧ 𝐴 ⊆ ℝ ) ) → ∃ 𝑧 ∈ 𝐴 ( 𝑦 + 1 ) ≤ 𝑧 ) |
| 80 | 79 | ancoms | ⊢ ( ( ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ∧ 𝐴 ⊆ ℝ ) ∧ ( 𝑦 + 1 ) ∈ ℝ ) → ∃ 𝑧 ∈ 𝐴 ( 𝑦 + 1 ) ≤ 𝑧 ) |
| 81 | 75 80 | sylan2 | ⊢ ( ( ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ∧ 𝐴 ⊆ ℝ ) ∧ 𝑦 ∈ ℝ ) → ∃ 𝑧 ∈ 𝐴 ( 𝑦 + 1 ) ≤ 𝑧 ) |
| 82 | ssel2 | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝑧 ∈ 𝐴 ) → 𝑧 ∈ ℝ ) | |
| 83 | ltp1 | ⊢ ( 𝑦 ∈ ℝ → 𝑦 < ( 𝑦 + 1 ) ) | |
| 84 | 83 | adantr | ⊢ ( ( 𝑦 ∈ ℝ ∧ 𝑧 ∈ ℝ ) → 𝑦 < ( 𝑦 + 1 ) ) |
| 85 | 75 | ancli | ⊢ ( 𝑦 ∈ ℝ → ( 𝑦 ∈ ℝ ∧ ( 𝑦 + 1 ) ∈ ℝ ) ) |
| 86 | ltletr | ⊢ ( ( 𝑦 ∈ ℝ ∧ ( 𝑦 + 1 ) ∈ ℝ ∧ 𝑧 ∈ ℝ ) → ( ( 𝑦 < ( 𝑦 + 1 ) ∧ ( 𝑦 + 1 ) ≤ 𝑧 ) → 𝑦 < 𝑧 ) ) | |
| 87 | 86 | 3expa | ⊢ ( ( ( 𝑦 ∈ ℝ ∧ ( 𝑦 + 1 ) ∈ ℝ ) ∧ 𝑧 ∈ ℝ ) → ( ( 𝑦 < ( 𝑦 + 1 ) ∧ ( 𝑦 + 1 ) ≤ 𝑧 ) → 𝑦 < 𝑧 ) ) |
| 88 | 85 87 | sylan | ⊢ ( ( 𝑦 ∈ ℝ ∧ 𝑧 ∈ ℝ ) → ( ( 𝑦 < ( 𝑦 + 1 ) ∧ ( 𝑦 + 1 ) ≤ 𝑧 ) → 𝑦 < 𝑧 ) ) |
| 89 | 84 88 | mpand | ⊢ ( ( 𝑦 ∈ ℝ ∧ 𝑧 ∈ ℝ ) → ( ( 𝑦 + 1 ) ≤ 𝑧 → 𝑦 < 𝑧 ) ) |
| 90 | 89 | ancoms | ⊢ ( ( 𝑧 ∈ ℝ ∧ 𝑦 ∈ ℝ ) → ( ( 𝑦 + 1 ) ≤ 𝑧 → 𝑦 < 𝑧 ) ) |
| 91 | 82 90 | sylan | ⊢ ( ( ( 𝐴 ⊆ ℝ ∧ 𝑧 ∈ 𝐴 ) ∧ 𝑦 ∈ ℝ ) → ( ( 𝑦 + 1 ) ≤ 𝑧 → 𝑦 < 𝑧 ) ) |
| 92 | 91 | an32s | ⊢ ( ( ( 𝐴 ⊆ ℝ ∧ 𝑦 ∈ ℝ ) ∧ 𝑧 ∈ 𝐴 ) → ( ( 𝑦 + 1 ) ≤ 𝑧 → 𝑦 < 𝑧 ) ) |
| 93 | 92 | reximdva | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝑦 ∈ ℝ ) → ( ∃ 𝑧 ∈ 𝐴 ( 𝑦 + 1 ) ≤ 𝑧 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) |
| 94 | 93 | adantll | ⊢ ( ( ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ∧ 𝐴 ⊆ ℝ ) ∧ 𝑦 ∈ ℝ ) → ( ∃ 𝑧 ∈ 𝐴 ( 𝑦 + 1 ) ≤ 𝑧 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) |
| 95 | 81 94 | mpd | ⊢ ( ( ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ∧ 𝐴 ⊆ ℝ ) ∧ 𝑦 ∈ ℝ ) → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) |
| 96 | 95 | exp31 | ⊢ ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 → ( 𝐴 ⊆ ℝ → ( 𝑦 ∈ ℝ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 97 | 96 | a1dd | ⊢ ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 → ( 𝐴 ⊆ ℝ → ( 𝑦 < +∞ → ( 𝑦 ∈ ℝ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 98 | 97 | com4r | ⊢ ( 𝑦 ∈ ℝ → ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 → ( 𝐴 ⊆ ℝ → ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 99 | xrltnr | ⊢ ( +∞ ∈ ℝ* → ¬ +∞ < +∞ ) | |
| 100 | 67 99 | ax-mp | ⊢ ¬ +∞ < +∞ |
| 101 | breq1 | ⊢ ( 𝑦 = +∞ → ( 𝑦 < +∞ ↔ +∞ < +∞ ) ) | |
| 102 | 100 101 | mtbiri | ⊢ ( 𝑦 = +∞ → ¬ 𝑦 < +∞ ) |
| 103 | 102 | pm2.21d | ⊢ ( 𝑦 = +∞ → ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) |
| 104 | 103 | 2a1d | ⊢ ( 𝑦 = +∞ → ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 → ( 𝐴 ⊆ ℝ → ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 105 | 0re | ⊢ 0 ∈ ℝ | |
| 106 | breq1 | ⊢ ( 𝑥 = 0 → ( 𝑥 ≤ 𝑧 ↔ 0 ≤ 𝑧 ) ) | |
| 107 | 106 | rexbidv | ⊢ ( 𝑥 = 0 → ( ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ↔ ∃ 𝑧 ∈ 𝐴 0 ≤ 𝑧 ) ) |
| 108 | 107 | rspcva | ⊢ ( ( 0 ∈ ℝ ∧ ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ) → ∃ 𝑧 ∈ 𝐴 0 ≤ 𝑧 ) |
| 109 | 105 108 | mpan | ⊢ ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 → ∃ 𝑧 ∈ 𝐴 0 ≤ 𝑧 ) |
| 110 | 82 24 | syl | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝑧 ∈ 𝐴 ) → -∞ < 𝑧 ) |
| 111 | 110 | a1d | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝑧 ∈ 𝐴 ) → ( 0 ≤ 𝑧 → -∞ < 𝑧 ) ) |
| 112 | 111 | reximdva | ⊢ ( 𝐴 ⊆ ℝ → ( ∃ 𝑧 ∈ 𝐴 0 ≤ 𝑧 → ∃ 𝑧 ∈ 𝐴 -∞ < 𝑧 ) ) |
| 113 | 109 112 | mpan9 | ⊢ ( ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ∧ 𝐴 ⊆ ℝ ) → ∃ 𝑧 ∈ 𝐴 -∞ < 𝑧 ) |
| 114 | 113 36 | imbitrrid | ⊢ ( 𝑦 = -∞ → ( ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ∧ 𝐴 ⊆ ℝ ) → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) |
| 115 | 114 | a1dd | ⊢ ( 𝑦 = -∞ → ( ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ∧ 𝐴 ⊆ ℝ ) → ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 116 | 115 | expd | ⊢ ( 𝑦 = -∞ → ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 → ( 𝐴 ⊆ ℝ → ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 117 | 98 104 116 | 3jaoi | ⊢ ( ( 𝑦 ∈ ℝ ∨ 𝑦 = +∞ ∨ 𝑦 = -∞ ) → ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 → ( 𝐴 ⊆ ℝ → ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 118 | 12 117 | sylbi | ⊢ ( 𝑦 ∈ ℝ* → ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 → ( 𝐴 ⊆ ℝ → ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 119 | 118 | com13 | ⊢ ( 𝐴 ⊆ ℝ → ( ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 → ( 𝑦 ∈ ℝ* → ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 120 | 119 | imp | ⊢ ( ( 𝐴 ⊆ ℝ ∧ ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ) → ( 𝑦 ∈ ℝ* → ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 121 | 120 | ralrimiv | ⊢ ( ( 𝐴 ⊆ ℝ ∧ ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ) → ∀ 𝑦 ∈ ℝ* ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) |
| 122 | 74 121 | jca | ⊢ ( ( 𝐴 ⊆ ℝ ∧ ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ) → ( ∀ 𝑦 ∈ 𝐴 ¬ +∞ < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 123 | breq1 | ⊢ ( 𝑥 = +∞ → ( 𝑥 < 𝑦 ↔ +∞ < 𝑦 ) ) | |
| 124 | 123 | notbid | ⊢ ( 𝑥 = +∞ → ( ¬ 𝑥 < 𝑦 ↔ ¬ +∞ < 𝑦 ) ) |
| 125 | 124 | ralbidv | ⊢ ( 𝑥 = +∞ → ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ↔ ∀ 𝑦 ∈ 𝐴 ¬ +∞ < 𝑦 ) ) |
| 126 | breq2 | ⊢ ( 𝑥 = +∞ → ( 𝑦 < 𝑥 ↔ 𝑦 < +∞ ) ) | |
| 127 | 126 | imbi1d | ⊢ ( 𝑥 = +∞ → ( ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ↔ ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 128 | 127 | ralbidv | ⊢ ( 𝑥 = +∞ → ( ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ↔ ∀ 𝑦 ∈ ℝ* ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 129 | 125 128 | anbi12d | ⊢ ( 𝑥 = +∞ → ( ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ↔ ( ∀ 𝑦 ∈ 𝐴 ¬ +∞ < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) ) |
| 130 | 129 | rspcev | ⊢ ( ( +∞ ∈ ℝ* ∧ ( ∀ 𝑦 ∈ 𝐴 ¬ +∞ < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 131 | 67 122 130 | sylancr | ⊢ ( ( 𝐴 ⊆ ℝ ∧ ∀ 𝑥 ∈ ℝ ∃ 𝑧 ∈ 𝐴 𝑥 ≤ 𝑧 ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 132 | 66 131 | syldan | ⊢ ( ( 𝐴 ⊆ ℝ ∧ ¬ ∃ 𝑥 ∈ ℝ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 133 | 132 | adantlr | ⊢ ( ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) ∧ ¬ ∃ 𝑥 ∈ ℝ ∀ 𝑦 ∈ 𝐴 𝑦 ≤ 𝑥 ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 134 | 50 133 | pm2.61dan | ⊢ ( ( 𝐴 ⊆ ℝ ∧ 𝐴 ≠ ∅ ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 135 | mnfxr | ⊢ -∞ ∈ ℝ* | |
| 136 | ral0 | ⊢ ∀ 𝑦 ∈ ∅ ¬ -∞ < 𝑦 | |
| 137 | nltmnf | ⊢ ( 𝑦 ∈ ℝ* → ¬ 𝑦 < -∞ ) | |
| 138 | 137 | pm2.21d | ⊢ ( 𝑦 ∈ ℝ* → ( 𝑦 < -∞ → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) |
| 139 | 138 | rgen | ⊢ ∀ 𝑦 ∈ ℝ* ( 𝑦 < -∞ → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) |
| 140 | 136 139 | pm3.2i | ⊢ ( ∀ 𝑦 ∈ ∅ ¬ -∞ < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < -∞ → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) |
| 141 | breq1 | ⊢ ( 𝑥 = -∞ → ( 𝑥 < 𝑦 ↔ -∞ < 𝑦 ) ) | |
| 142 | 141 | notbid | ⊢ ( 𝑥 = -∞ → ( ¬ 𝑥 < 𝑦 ↔ ¬ -∞ < 𝑦 ) ) |
| 143 | 142 | ralbidv | ⊢ ( 𝑥 = -∞ → ( ∀ 𝑦 ∈ ∅ ¬ 𝑥 < 𝑦 ↔ ∀ 𝑦 ∈ ∅ ¬ -∞ < 𝑦 ) ) |
| 144 | breq2 | ⊢ ( 𝑥 = -∞ → ( 𝑦 < 𝑥 ↔ 𝑦 < -∞ ) ) | |
| 145 | 144 | imbi1d | ⊢ ( 𝑥 = -∞ → ( ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ↔ ( 𝑦 < -∞ → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) ) |
| 146 | 145 | ralbidv | ⊢ ( 𝑥 = -∞ → ( ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ↔ ∀ 𝑦 ∈ ℝ* ( 𝑦 < -∞ → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) ) |
| 147 | 143 146 | anbi12d | ⊢ ( 𝑥 = -∞ → ( ( ∀ 𝑦 ∈ ∅ ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) ↔ ( ∀ 𝑦 ∈ ∅ ¬ -∞ < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < -∞ → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) ) ) |
| 148 | 147 | rspcev | ⊢ ( ( -∞ ∈ ℝ* ∧ ( ∀ 𝑦 ∈ ∅ ¬ -∞ < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < -∞ → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ ∅ ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) ) |
| 149 | 135 140 148 | mp2an | ⊢ ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ ∅ ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) |
| 150 | 149 | a1i | ⊢ ( 𝐴 ⊆ ℝ → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ ∅ ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ ∅ 𝑦 < 𝑧 ) ) ) |
| 151 | 6 134 150 | pm2.61ne | ⊢ ( 𝐴 ⊆ ℝ → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 152 | 151 | adantl | ⊢ ( ( 𝐴 ⊆ ℝ* ∧ 𝐴 ⊆ ℝ ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 153 | ssel | ⊢ ( 𝐴 ⊆ ℝ* → ( 𝑦 ∈ 𝐴 → 𝑦 ∈ ℝ* ) ) | |
| 154 | 153 70 | syl6 | ⊢ ( 𝐴 ⊆ ℝ* → ( 𝑦 ∈ 𝐴 → ¬ +∞ < 𝑦 ) ) |
| 155 | 154 | ralrimiv | ⊢ ( 𝐴 ⊆ ℝ* → ∀ 𝑦 ∈ 𝐴 ¬ +∞ < 𝑦 ) |
| 156 | breq2 | ⊢ ( 𝑧 = +∞ → ( 𝑦 < 𝑧 ↔ 𝑦 < +∞ ) ) | |
| 157 | 156 | rspcev | ⊢ ( ( +∞ ∈ 𝐴 ∧ 𝑦 < +∞ ) → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) |
| 158 | 157 | ex | ⊢ ( +∞ ∈ 𝐴 → ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) |
| 159 | 158 | ralrimivw | ⊢ ( +∞ ∈ 𝐴 → ∀ 𝑦 ∈ ℝ* ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) |
| 160 | 155 159 | anim12i | ⊢ ( ( 𝐴 ⊆ ℝ* ∧ +∞ ∈ 𝐴 ) → ( ∀ 𝑦 ∈ 𝐴 ¬ +∞ < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < +∞ → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 161 | 67 160 130 | sylancr | ⊢ ( ( 𝐴 ⊆ ℝ* ∧ +∞ ∈ 𝐴 ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |
| 162 | 152 161 | jaodan | ⊢ ( ( 𝐴 ⊆ ℝ* ∧ ( 𝐴 ⊆ ℝ ∨ +∞ ∈ 𝐴 ) ) → ∃ 𝑥 ∈ ℝ* ( ∀ 𝑦 ∈ 𝐴 ¬ 𝑥 < 𝑦 ∧ ∀ 𝑦 ∈ ℝ* ( 𝑦 < 𝑥 → ∃ 𝑧 ∈ 𝐴 𝑦 < 𝑧 ) ) ) |