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| Mirrors > Home > ILE Home > Th. List > celaront | GIF version | ||
| Description: "Celaront", one of the syllogisms of Aristotelian logic. No 𝜑 is 𝜓, all 𝜒 is 𝜑, and some 𝜒 exist, therefore some 𝜒 is not 𝜓. (In Aristotelian notation, EAO-1: MeP and SaM therefore SoP.) For example, given "No reptiles have fur", "All snakes are reptiles.", and "Snakes exist.", prove "Some snakes have no fur". Note the existence hypothesis. Example from https://en.wikipedia.org/wiki/Syllogism. (Contributed by David A. Wheeler, 27-Aug-2016.) (Revised by David A. Wheeler, 2-Sep-2016.) |
| Ref | Expression |
|---|---|
| celaront.maj | ⊢ ∀𝑥(𝜑 → ¬ 𝜓) |
| celaront.min | ⊢ ∀𝑥(𝜒 → 𝜑) |
| celaront.e | ⊢ ∃𝑥𝜒 |
| Ref | Expression |
|---|---|
| celaront | ⊢ ∃𝑥(𝜒 ∧ ¬ 𝜓) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | celaront.maj | . 2 ⊢ ∀𝑥(𝜑 → ¬ 𝜓) | |
| 2 | celaront.min | . 2 ⊢ ∀𝑥(𝜒 → 𝜑) | |
| 3 | celaront.e | . 2 ⊢ ∃𝑥𝜒 | |
| 4 | 1, 2, 3 | barbari 2182 | 1 ⊢ ∃𝑥(𝜒 ∧ ¬ 𝜓) |
| Colors of variables: wff set class |
| Syntax hints: ¬ wn 3 → wi 4 ∧ wa 104 ∀wal 1396 ∃wex 1541 |
| 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-5 1496 ax-gen 1498 ax-ie1 1542 ax-ie2 1543 ax-4 1559 ax-ial 1583 |
| This theorem depends on definitions: df-bi 117 |
| This theorem is referenced by: (None) |
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