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Mirrors > Home > NFE Home > Th. List > fresison | GIF version |
Description: "Fresison", one of the syllogisms of Aristotelian logic. No φ is ψ (PeM), and some ψ is χ (MiS), therefore some χ is not φ (SoP). (In Aristotelian notation, EIO-4: PeM and MiS therefore SoP.) (Contributed by David A. Wheeler, 28-Aug-2016.) (Revised by David A. Wheeler, 2-Sep-2016.) |
Ref | Expression |
---|---|
fresison.maj | ⊢ ∀x(φ → ¬ ψ) |
fresison.min | ⊢ ∃x(ψ ∧ χ) |
Ref | Expression |
---|---|
fresison | ⊢ ∃x(χ ∧ ¬ φ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | fresison.min | . 2 ⊢ ∃x(ψ ∧ χ) | |
2 | simpr 447 | . . . 4 ⊢ ((ψ ∧ χ) → χ) | |
3 | fresison.maj | . . . . . . 7 ⊢ ∀x(φ → ¬ ψ) | |
4 | 3 | spi 1753 | . . . . . 6 ⊢ (φ → ¬ ψ) |
5 | 4 | con2i 112 | . . . . 5 ⊢ (ψ → ¬ φ) |
6 | 5 | adantr 451 | . . . 4 ⊢ ((ψ ∧ χ) → ¬ φ) |
7 | 2, 6 | jca 518 | . . 3 ⊢ ((ψ ∧ χ) → (χ ∧ ¬ φ)) |
8 | 7 | eximi 1576 | . 2 ⊢ (∃x(ψ ∧ χ) → ∃x(χ ∧ ¬ φ)) |
9 | 1, 8 | ax-mp 5 | 1 ⊢ ∃x(χ ∧ ¬ φ) |
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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