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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 2157 | 1 ⊢ ∃𝑥(𝜒 ∧ ¬ 𝜓) |
| Colors of variables: wff set class |
| Syntax hints: ¬ wn 3 → wi 4 ∧ wa 104 ∀wal 1371 ∃wex 1516 |
| 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 1471 ax-gen 1473 ax-ie1 1517 ax-ie2 1518 ax-4 1534 ax-ial 1558 |
| This theorem depends on definitions: df-bi 117 |
| This theorem is referenced by: (None) |
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