Metamath Proof Explorer


Theorem 3adantl1

Description: Deduction adding a conjunct to antecedent. (Contributed by NM, 24-Feb-2005)

Ref Expression
Hypothesis 3adantl.1 ⊢ φ ∧ ψ ∧ χ → θ
Assertion 3adantl1 ⊢ τ ∧ φ ∧ ψ ∧ χ → θ

Proof

Step Hyp Ref Expression
1 3adantl.1 ⊢ φ ∧ ψ ∧ χ → θ
2 3simpc ⊢ τ ∧ φ ∧ ψ → φ ∧ ψ
3 2 1 sylan ⊢ τ ∧ φ ∧ ψ ∧ χ → θ