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| Mirrors > Home > ILE Home > Th. List > pm5.75 | GIF version | ||
| Description: Theorem *5.75 of [WhiteheadRussell] p. 126. (Contributed by NM, 3-Jan-2005.) (Proof shortened by Andrew Salmon, 7-May-2011.) (Proof shortened by Wolf Lammen, 23-Dec-2012.) |
| Ref | Expression |
|---|---|
| pm5.75 | ⊢ (((𝜒 → ¬ 𝜓) ∧ (𝜑 ↔ (𝜓 ∨ 𝜒))) → ((𝜑 ∧ ¬ 𝜓) ↔ 𝜒)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | anbi1 466 | . . 3 ⊢ ((𝜑 ↔ (𝜓 ∨ 𝜒)) → ((𝜑 ∧ ¬ 𝜓) ↔ ((𝜓 ∨ 𝜒) ∧ ¬ 𝜓))) | |
| 2 | orcom 729 | . . . . 5 ⊢ ((𝜓 ∨ 𝜒) ↔ (𝜒 ∨ 𝜓)) | |
| 3 | 2 | anbi1i 458 | . . . 4 ⊢ (((𝜓 ∨ 𝜒) ∧ ¬ 𝜓) ↔ ((𝜒 ∨ 𝜓) ∧ ¬ 𝜓)) |
| 4 | pm5.61 795 | . . . 4 ⊢ (((𝜒 ∨ 𝜓) ∧ ¬ 𝜓) ↔ (𝜒 ∧ ¬ 𝜓)) | |
| 5 | 3, 4 | bitri 184 | . . 3 ⊢ (((𝜓 ∨ 𝜒) ∧ ¬ 𝜓) ↔ (𝜒 ∧ ¬ 𝜓)) |
| 6 | 1, 5 | bitrdi 196 | . 2 ⊢ ((𝜑 ↔ (𝜓 ∨ 𝜒)) → ((𝜑 ∧ ¬ 𝜓) ↔ (𝜒 ∧ ¬ 𝜓))) |
| 7 | pm4.71 389 | . . . 4 ⊢ ((𝜒 → ¬ 𝜓) ↔ (𝜒 ↔ (𝜒 ∧ ¬ 𝜓))) | |
| 8 | 7 | biimpi 120 | . . 3 ⊢ ((𝜒 → ¬ 𝜓) → (𝜒 ↔ (𝜒 ∧ ¬ 𝜓))) |
| 9 | 8 | bicomd 141 | . 2 ⊢ ((𝜒 → ¬ 𝜓) → ((𝜒 ∧ ¬ 𝜓) ↔ 𝜒)) |
| 10 | 6, 9 | sylan9bbr 463 | 1 ⊢ (((𝜒 → ¬ 𝜓) ∧ (𝜑 ↔ (𝜓 ∨ 𝜒))) → ((𝜑 ∧ ¬ 𝜓) ↔ 𝜒)) |
| Colors of variables: wff set class |
| Syntax hints: ¬ wn 3 → wi 4 ∧ wa 104 ↔ wb 105 ∨ wo 709 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-in2 616 ax-io 710 |
| This theorem depends on definitions: df-bi 117 |
| This theorem is referenced by: (None) |
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