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Mirrors > Home > ILE Home > Th. List > Mathboxes > 2spim | GIF version |
Description: Double substitution, as in spim 1666. (Contributed by BJ, 17-Oct-2019.) |
Ref | Expression |
---|---|
2spim.nfx | ⊢ Ⅎ𝑥𝜒 |
2spim.nfz | ⊢ Ⅎ𝑧𝜒 |
2spim.1 | ⊢ ((𝑥 = 𝑦 ∧ 𝑧 = 𝑡) → (𝜓 → 𝜒)) |
Ref | Expression |
---|---|
2spim | ⊢ (∀𝑧∀𝑥𝜓 → 𝜒) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 2spim.nfz | . 2 ⊢ Ⅎ𝑧𝜒 | |
2 | 2spim.nfx | . . . 4 ⊢ Ⅎ𝑥𝜒 | |
3 | 2 | a1i 9 | . . 3 ⊢ (𝑧 = 𝑡 → Ⅎ𝑥𝜒) |
4 | 2spim.1 | . . . . 5 ⊢ ((𝑥 = 𝑦 ∧ 𝑧 = 𝑡) → (𝜓 → 𝜒)) | |
5 | 4 | expcom 114 | . . . 4 ⊢ (𝑧 = 𝑡 → (𝑥 = 𝑦 → (𝜓 → 𝜒))) |
6 | 5 | alrimiv 1795 | . . 3 ⊢ (𝑧 = 𝑡 → ∀𝑥(𝑥 = 𝑦 → (𝜓 → 𝜒))) |
7 | 3, 6 | spimd 10576 | . 2 ⊢ (𝑧 = 𝑡 → (∀𝑥𝜓 → 𝜒)) |
8 | 1, 7 | spim 1666 | 1 ⊢ (∀𝑧∀𝑥𝜓 → 𝜒) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 102 ∀wal 1282 Ⅎwnf 1389 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-5 1376 ax-gen 1378 ax-ie1 1422 ax-ie2 1423 ax-4 1440 ax-17 1459 ax-i9 1463 ax-ial 1467 |
This theorem depends on definitions: df-bi 115 df-nf 1390 |
This theorem is referenced by: ch2var 10578 |
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