Metamath Proof Explorer


Theorem stoic1b

Description: Stoic logic Thema 1 (part b). The other part of thema 1 of Stoic logic; see stoic1a . (Contributed by David A. Wheeler, 16-Feb-2019)

Ref Expression
Hypothesis stoic1.1 φ ψ θ
Assertion stoic1b ψ ¬ θ ¬ φ

Proof

Step Hyp Ref Expression
1 stoic1.1 φ ψ θ
2 1 ancoms ψ φ θ
3 2 stoic1a ψ ¬ θ ¬ φ