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Theorem festino 2309
Description: "Festino", one of the syllogisms of Aristotelian logic. No φ is ψ, and some χ is ψ, therefore some χ is not φ. (In Aristotelian notation, EIO-2: PeM and SiM therefore SoP.) (Contributed by David A. Wheeler, 25-Nov-2016.)
Hypotheses
Ref Expression
festino.maj ⊢ ∀x(φ → ¬ ψ)
festino.min ⊢ ∃x(χ ∧ ψ)
Assertion
Ref Expression
festino ⊢ ∃x(χ ∧ ¬ φ)

Proof of Theorem festino
StepHypRef Expression
1 festino.min . 2 ⊢ ∃x(χ ∧ ψ)
2 festino.maj . . . . . 6 ⊢ ∀x(φ → ¬ ψ)
32spi 1753 . . . . 5 ⊢ (φ → ¬ ψ)
43con2i 112 . . . 4 ⊢ (ψ → ¬ φ)
54anim2i 552 . . 3 ⊢ ((χ ∧ ψ) → (χ ∧ ¬ φ))
65eximi 1576 . 2 ⊢ (∃x(χ ∧ ψ) → ∃x(χ ∧ ¬ φ))
71, 6ax-mp 5 1 ⊢ ∃x(χ ∧ ¬ φ)
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ∧ wa 358  ∀wal 1540  ∃wex 1541
This proof depends on 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 proof depends on definitions:  df-bi 177  df-an 360  df-ex 1542
This theorem is used by: (None)
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