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| Mirrors > Home > NFE Home > Th. List > ferison | GIF version | ||
| Description: "Ferison", one of the syllogisms of Aristotelian logic. No φ is ψ, and some φ is χ, therefore some χ is not ψ. (In Aristotelian notation, EIO-3: MeP and MiS therefore SoP.) (Contributed by David A. Wheeler, 28-Aug-2016.) (Revised by David A. Wheeler, 2-Sep-2016.) |
| Ref | Expression |
|---|---|
| ferison.maj | ⊢ ∀x(φ → ¬ ψ) |
| ferison.min | ⊢ ∃x(φ ∧ χ) |
| Ref | Expression |
|---|---|
| ferison | ⊢ ∃x(χ ∧ ¬ ψ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ferison.maj | . 2 ⊢ ∀x(φ → ¬ ψ) | |
| 2 | ferison.min | . 2 ⊢ ∃x(φ ∧ χ) | |
| 3 | 1, 2 | datisi 2313 | 1 ⊢ ∃x(χ ∧ ¬ ψ) |
| Colors of variables: wff setvar class |
| Syntax hints: ¬ wn 3 → wi 4 ∧ wa 358 ∀wal 1540 ∃wex 1541 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1546 ax-5 1557 ax-17 1616 ax-9 1654 ax-8 1675 ax-11 1746 |
| This theorem depends on definitions: df-bi 177 df-an 360 df-ex 1542 |
| This theorem is referenced by: (None) |
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