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Step * 1 of Lemma not-not-excluded-middle-quot-true


1. P : ℙ
2. ¬⇃(P ∨ (¬P))
⊢ False
BY
{ Assert ⌜¬(P ∨ (¬P))⌝⋅ }

1
.....assertion..... 
1. P : ℙ
2. ¬⇃(P ∨ (¬P))
⊢ ¬(P ∨ (¬P))

2
1. P : ℙ
2. ¬⇃(P ∨ (¬P))
3. ¬(P ∨ (¬P))
⊢ False

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Latex:

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Latex:

1.  P  :  \mBbbP{}
2.  \mneg{}\00D9(P  \mvee{}  (\mneg{}P))
\mvdash{}  False


By

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Latex:
Assert  \mkleeneopen{}\mneg{}(P  \mvee{}  (\mneg{}P))\mkleeneclose{}\mcdot{}

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