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Theorem alseu-no-surprise 50616
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 50584 by alseuals 50602. For a contrast, see alimp-surprise 50558. (Contributed by David A. Wheeler, 21-Jul-2026.)
Assertion
Ref Expression
alseu-no-surprise ¬ (∀∃!𝑥(𝜑𝜓) ∧ ∀∃!𝑥(𝜑 → ¬ 𝜓))

Proof of Theorem alseu-no-surprise
StepHypRef Expression
1 als-no-surprise 50584 . 2 ¬ (∀∃𝑥(𝜑𝜓) ∧ ∀∃𝑥(𝜑 → ¬ 𝜓))
2 alseuals 50602 . . 3 (∀∃!𝑥(𝜑𝜓) → ∀∃𝑥(𝜑𝜓))
3 alseuals 50602 . . 3 (∀∃!𝑥(𝜑 → ¬ 𝜓) → ∀∃𝑥(𝜑 → ¬ 𝜓))
42, 3anim12i 624 . 2 ((∀∃!𝑥(𝜑𝜓) ∧ ∀∃!𝑥(𝜑 → ¬ 𝜓)) → (∀∃𝑥(𝜑𝜓) ∧ ∀∃𝑥(𝜑 → ¬ 𝜓)))
51, 4mto 200 1 ¬ (∀∃!𝑥(𝜑𝜓) ∧ ∀∃!𝑥(𝜑 → ¬ 𝜓))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wa 400  ∀∃wals 50564  ∀∃!walseu 50597
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1825  ax-4 1839
This theorem depends on definitions:  df-bi 210  df-an 401  df-3an 1105  df-ex 1810  df-eu 2597  df-als 50566  df-alseu 50599
This theorem is referenced by: (None)
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