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Theorem camestros 2312
Description: "Camestros", one of the syllogisms of Aristotelian logic. All φ is ψ, no χ is ψ, and χ exist, therefore some χ is not φ. (In Aristotelian notation, AEO-2: PaM and SeM therefore SoP.) For example, "All horses have hooves", "No humans have hooves", and humans exist, therefore "Some humans are not horses". (Contributed by David A. Wheeler, 28-Aug-2016.) (Revised by David A. Wheeler, 2-Sep-2016.)
Hypotheses
Ref Expression
camestros.maj ⊢ ∀x(φ → ψ)
camestros.min ⊢ ∀x(χ → ¬ ψ)
camestros.e ⊢ ∃xχ
Assertion
Ref Expression
camestros ⊢ ∃x(χ ∧ ¬ φ)

Proof of Theorem camestros
StepHypRef Expression
1 camestros.e . 2 ⊢ ∃xχ
2 camestros.min . . . . . 6 ⊢ ∀x(χ → ¬ ψ)
32spi 1753 . . . . 5 ⊢ (χ → ¬ ψ)
4 camestros.maj . . . . . 6 ⊢ ∀x(φ → ψ)
54spi 1753 . . . . 5 ⊢ (φ → ψ)
63, 5nsyl 113 . . . 4 ⊢ (χ → ¬ φ)
76ancli 534 . . 3 ⊢ (χ → (χ ∧ ¬ φ))
87eximi 1576 . 2 ⊢ (∃xχ → ∃x(χ ∧ ¬ φ))
91, 8ax-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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