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Theorem nfale2 43362
Description: An inner existential quantifier's variable is bound. (Contributed by SN, 11-Feb-2026.)
Assertion
Ref Expression
nfale2 Ⅎ𝑥∀𝑦∃𝑥𝜑

Proof of Theorem nfale2
StepHypRef Expression
1 hbe1 2179 . 2 (∃𝑥𝜑 → ∀𝑥∃𝑥𝜑)
21nfalh 43360 1 Ⅎ𝑥∀𝑦∃𝑥𝜑
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  ∀wal 1567  ∃wex 1811  Ⅎwnf 1815
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-10 2177  ax-11 2193
This proof depends on definitions:  df-bi 210  df-ex 1812  df-nf 1816
This theorem is used by: (None)
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