Metamath Proof Explorer


Theorem intnanrt

Description: Introduction of conjunct inside of a contradiction. Would be used in elfvov1 . (Contributed by SN, 18-May-2025)

Ref Expression
Assertion intnanrt ¬ φ ¬ φ ψ

Proof

Step Hyp Ref Expression
1 simpl φ ψ φ
2 1 con3i ¬ φ ¬ φ ψ