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| Mirrors > Home > ILE Home > Th. List > exlimdd | GIF version | ||
| Description: Existential elimination rule of natural deduction. (Contributed by Mario Carneiro, 9-Feb-2017.) |
| Ref | Expression |
|---|---|
| exlimdd.1 | ⊢ Ⅎ𝑥𝜑 |
| exlimdd.2 | ⊢ Ⅎ𝑥𝜒 |
| exlimdd.3 | ⊢ (𝜑 → ∃𝑥𝜓) |
| exlimdd.4 | ⊢ ((𝜑 ∧ 𝜓) → 𝜒) |
| Ref | Expression |
|---|---|
| exlimdd | ⊢ (𝜑 → 𝜒) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | exlimdd.3 | . 2 ⊢ (𝜑 → ∃𝑥𝜓) | |
| 2 | exlimdd.1 | . . 3 ⊢ Ⅎ𝑥𝜑 | |
| 3 | exlimdd.2 | . . 3 ⊢ Ⅎ𝑥𝜒 | |
| 4 | exlimdd.4 | . . . 4 ⊢ ((𝜑 ∧ 𝜓) → 𝜒) | |
| 5 | 4 | ex 115 | . . 3 ⊢ (𝜑 → (𝜓 → 𝜒)) |
| 6 | 2, 3, 5 | exlimd 1611 | . 2 ⊢ (𝜑 → (∃𝑥𝜓 → 𝜒)) |
| 7 | 1, 6 | mpd 13 | 1 ⊢ (𝜑 → 𝜒) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ∧ wa 104 Ⅎwnf 1474 ∃wex 1506 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia3 108 ax-5 1461 ax-gen 1463 ax-ie2 1508 ax-4 1524 |
| This theorem depends on definitions: df-bi 117 df-nf 1475 |
| This theorem is referenced by: fvmptdf 5649 ovmpodf 6054 exmidfodomrlemr 7269 exmidfodomrlemrALT 7270 ltexprlemm 7667 dfgrp3mlem 13230 |
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