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Metamath Proof Explorer


Theorem mpnanrd

Description: Eliminate the right side of a negated conjunction in an implication. (Contributed by ML, 17-Oct-2020)

Ref Expression
Hypotheses mpnanrd.1 φ ψ
mpnanrd.2 φ ¬ ψ χ
Assertion mpnanrd φ ¬ χ

Proof

Step Hyp Ref Expression
1 mpnanrd.1 φ ψ
2 mpnanrd.2 φ ¬ ψ χ
3 imnan ψ ¬ χ ¬ ψ χ
4 2 3 sylibr φ ψ ¬ χ
5 1 4 mpd φ ¬ χ