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NOT_PFORALL_CONV                                           (PairRules)
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NOT_PFORALL_CONV : conv

KEYWORDS
conversion, quantifier, universal, negation.

LIBRARY
pair

SYNOPSIS
Moves negation inwards through a paired universal quantification.

DESCRIBE
When applied to a term of the form {~(!p. t)}, the conversion
{NOT_PFORALL_CONV} returns the theorem:

   |- ~(!p. t) = (?p. ~t)

It is irrelevant whether any variables in {p} occur free in {t}.

FAILURE
Fails if applied to a term not of the form {~(!p. t)}.

SEEALSO
Conv.NOT_FORALL_CONV, PairRules.PEXISTS_NOT_CONV,
PairRules.PFORALL_NOT_CONV, PairRules.NOT_PEXISTS_CONV.

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