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Step * of Lemma not_functionality_wrt_iff

∀[P,Q:ℙ].  {¬P ⇐⇒ ¬Q} supposing P ⇐⇒ Q
BY
{ (Unfold `guard` 0 THEN Auto) }

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Latex:

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Latex:
\mforall{}[P,Q:\mBbbP{}].    \{\mneg{}P  \mLeftarrow{}{}\mRightarrow{}  \mneg{}Q\}  supposing  P  \mLeftarrow{}{}\mRightarrow{}  Q


By

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Latex:
(Unfold  `guard`  0  THEN  Auto)

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