Metamath Proof Explorer


Theorem 3orim123da

Description: Disjoin antecedents and consequents of three premises. (Contributed by Thierry Arnoux, 13-Jul-2026)

Ref Expression
Hypotheses 3orim123da.1 ⊢ φ → ψ ∨ θ ∨ η
3orim123da.2 ⊢ φ ∧ ψ → χ
3orim123da.3 ⊢ φ ∧ θ → τ
3orim123da.4 ⊢ φ ∧ η → ζ
Assertion 3orim123da ⊢ φ → χ ∨ τ ∨ ζ

Proof

Step Hyp Ref Expression
1 3orim123da.1 ⊢ φ → ψ ∨ θ ∨ η
2 3orim123da.2 ⊢ φ ∧ ψ → χ
3 3orim123da.3 ⊢ φ ∧ θ → τ
4 3orim123da.4 ⊢ φ ∧ η → ζ
5 2 ex ⊢ φ → ψ → χ
6 3 ex ⊢ φ → θ → τ
7 4 ex ⊢ φ → η → ζ
8 5 6 7 3orim123d ⊢ φ → ψ ∨ θ ∨ η → χ ∨ τ ∨ ζ
9 1 8 mpd ⊢ φ → χ ∨ τ ∨ ζ