Proof of Theorem psuband-P6
| Step | Hyp | Ref
| Expression |
| 1 | | andasim-P3.46a 356 |
. . . 4
⊢ ((𝜑 ∧ 𝜓) ↔
¬ (𝜑 → ¬ 𝜓)) |
| 2 | 1 | psubleq-P6 783 |
. . 3
⊢ ([𝑡 / 𝑥](𝜑 ∧ 𝜓) ↔
[𝑡 / 𝑥] ¬
(𝜑 → ¬ 𝜓)) |
| 3 | | psubneg-P6 788 |
. . 3
⊢ ([𝑡 / 𝑥] ¬ (𝜑 → ¬ 𝜓)
↔ ¬ [𝑡 / 𝑥](𝜑 → ¬
𝜓)) |
| 4 | | psubim-P6 791 |
. . . . 5
⊢ ([𝑡 / 𝑥](𝜑 → ¬ 𝜓)
↔ ([𝑡 / 𝑥]𝜑 → [𝑡 / 𝑥] ¬ 𝜓)) |
| 5 | | psubneg-P6 788 |
. . . . . 6
⊢ ([𝑡 / 𝑥] ¬ 𝜓 ↔ ¬ [𝑡 /
𝑥]𝜓) |
| 6 | 5 | subimr-P3.40b.RC 328 |
. . . . 5
⊢ (([𝑡 / 𝑥]𝜑 → [𝑡 / 𝑥] ¬ 𝜓) ↔
([𝑡 / 𝑥]𝜑 → ¬ [𝑡 /
𝑥]𝜓)) |
| 7 | 4, 6 | bitrns-P3.33c.RC 303 |
. . . 4
⊢ ([𝑡 / 𝑥](𝜑 → ¬ 𝜓)
↔ ([𝑡 / 𝑥]𝜑 → ¬
[𝑡 / 𝑥]𝜓)) |
| 8 | 7 | subneg-P3.39.RC 324 |
. . 3
⊢ (¬ [𝑡 / 𝑥](𝜑 → ¬ 𝜓)
↔ ¬ ([𝑡 / 𝑥]𝜑 → ¬
[𝑡 / 𝑥]𝜓)) |
| 9 | 2, 3, 8 | dbitrns-P4.16.RC 429 |
. 2
⊢ ([𝑡 / 𝑥](𝜑 ∧ 𝜓) ↔
¬ ([𝑡 / 𝑥]𝜑 → ¬
[𝑡 / 𝑥]𝜓)) |
| 10 | | andasim-P3.46a 356 |
. . 3
⊢ (([𝑡 / 𝑥]𝜑 ∧ [𝑡 / 𝑥]𝜓) ↔ ¬
([𝑡 / 𝑥]𝜑 → ¬ [𝑡 /
𝑥]𝜓)) |
| 11 | 10 | bisym-P3.33b.RC 299 |
. 2
⊢ (¬ ([𝑡 / 𝑥]𝜑 → ¬ [𝑡 /
𝑥]𝜓) ↔
([𝑡 / 𝑥]𝜑 ∧ [𝑡 / 𝑥]𝜓)) |
| 12 | 9, 11 | bitrns-P3.33c.RC 303 |
1
⊢ ([𝑡 / 𝑥](𝜑 ∧ 𝜓) ↔
([𝑡 / 𝑥]𝜑 ∧ [𝑡 / 𝑥]𝜓)) |