Is the proof below correct for the following premise?: ⊤ ⊢ (B → ¬B) → ¬B
1 B → ~B :AS
2 B :AS
3 ~B : → E1,2
4 ⊥
5 ~B :~I1-4
6 --
7 (B->~B)-> ~B :->I1-4
3
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Here is a natural deduction proof checker: proofs.openlogicproject.org– Natalie ClariusOct 25, 2020 at 20:51
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You should cite the rule name and source lines for ⊥, and the source lines for your last -> should be 1-5; otherwise your proof looks fine -- well done!– Natalie ClariusOct 25, 2020 at 20:54
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@lemontree thank you!!– PriOct 25, 2020 at 20:56
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