Proof of Theorem qcexandr-P6
| Step | Hyp | Ref
| Expression |
| 1 | | andasim-P3.46a 356 |
. 2
⊢ ((𝜑 ∧ ∃𝑥𝜓) ↔ ¬
(𝜑 → ¬ ∃𝑥𝜓)) |
| 2 | | andasim-P3.46a 356 |
. . . . 5
⊢ ((𝜑 ∧ 𝜓) ↔
¬ (𝜑 → ¬ 𝜓)) |
| 3 | 2 | subexinf-P5 608 |
. . . 4
⊢ (∃𝑥(𝜑 ∧ 𝜓) ↔ ∃𝑥
¬ (𝜑 → ¬ 𝜓)) |
| 4 | | exnegall-P5 598 |
. . . 4
⊢ (∃𝑥 ¬ (𝜑 →
¬ 𝜓) ↔ ¬ ∀𝑥(𝜑 → ¬
𝜓)) |
| 5 | | qcexandr-P6.1 |
. . . . . . . 8
⊢ Ⅎ𝑥𝜑 |
| 6 | 5 | qcallimr-P6 757 |
. . . . . . 7
⊢ ((𝜑 → ∀𝑥
¬ 𝜓) ↔ ∀𝑥(𝜑 → ¬
𝜓)) |
| 7 | 6 | bisym-P3.33b.RC 299 |
. . . . . 6
⊢ (∀𝑥(𝜑 → ¬
𝜓) ↔ (𝜑
→ ∀𝑥 ¬ 𝜓)) |
| 8 | | allnegex-P5 597 |
. . . . . . 7
⊢ (∀𝑥 ¬ 𝜓 ↔
¬ ∃𝑥𝜓) |
| 9 | 8 | subimr-P3.40b.RC 328 |
. . . . . 6
⊢ ((𝜑 → ∀𝑥
¬ 𝜓) ↔ (𝜑 → ¬ ∃𝑥𝜓)) |
| 10 | 7, 9 | bitrns-P3.33c.RC 303 |
. . . . 5
⊢ (∀𝑥(𝜑 → ¬
𝜓) ↔ (𝜑
→ ¬ ∃𝑥𝜓)) |
| 11 | 10 | subneg-P3.39.RC 324 |
. . . 4
⊢ (¬ ∀𝑥(𝜑 → ¬
𝜓) ↔ ¬ (𝜑 → ¬ ∃𝑥𝜓)) |
| 12 | 3, 4, 11 | dbitrns-P4.16.RC 429 |
. . 3
⊢ (∃𝑥(𝜑 ∧ 𝜓) ↔ ¬ (𝜑
→ ¬ ∃𝑥𝜓)) |
| 13 | 12 | bisym-P3.33b.RC 299 |
. 2
⊢ (¬ (𝜑 → ¬ ∃𝑥𝜓) ↔
∃𝑥(𝜑
∧ 𝜓)) |
| 14 | 1, 13 | bitrns-P3.33c.RC 303 |
1
⊢ ((𝜑 ∧ ∃𝑥𝜓) ↔
∃𝑥(𝜑
∧ 𝜓)) |