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Theorem alseu-no-surprise 51117
Description: Demonstrate that there is never a "surprise" when using the "all some one" quantifier, that is, it is never possible for the consequent to be both always true and always false. This follows from als-no-surprise 51085 by alseuals 51103. For a contrast, see alimp-surprise 51059. (Contributed by David A. Wheeler, 21-Jul-2026.)
Assertion
Ref Expression
alseu-no-surprise ¬ (∀∃!𝑥(𝜑 → 𝜓) ∧ ∀∃!𝑥(𝜑 → ¬ 𝜓))

Proof of Theorem alseu-no-surprise
StepHypRef Expression
1 als-no-surprise 51085 . 2 ¬ (∀∃𝑥(𝜑 → 𝜓) ∧ ∀∃𝑥(𝜑 → ¬ 𝜓))
2 alseuals 51103 . . 3 (∀∃!𝑥(𝜑 → 𝜓) → ∀∃𝑥(𝜑 → 𝜓))
3 alseuals 51103 . . 3 (∀∃!𝑥(𝜑 → ¬ 𝜓) → ∀∃𝑥(𝜑 → ¬ 𝜓))
42, 3anim12i 625 . 2 ((∀∃!𝑥(𝜑 → 𝜓) ∧ ∀∃!𝑥(𝜑 → ¬ 𝜓)) → (∀∃𝑥(𝜑 → 𝜓) ∧ ∀∃𝑥(𝜑 → ¬ 𝜓)))
51, 4mto 200 1 ¬ (∀∃!𝑥(𝜑 → 𝜓) ∧ ∀∃!𝑥(𝜑 → ¬ 𝜓))
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  ¬ wn 3   ∧ wa 401  ∀∃wals 51065  ∀∃!walseu 51098
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841
This proof depends on definitions:  df-bi 210  df-an 402  df-3an 1105  df-ex 1812  df-eu 2594  df-als 51067  df-alseu 51100
This theorem is used by: (None)
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