Metamath Proof Explorer


Theorem anbi1d

Description: Deduction adding a right conjunct to both sides of a logical equivalence. (Contributed by NM, 11-May-1993) (Proof shortened by Wolf Lammen, 16-Nov-2013)

Ref Expression
Hypothesis anbid.1 ⊢ φ → ψ ↔ χ
Assertion anbi1d ⊢ φ → ψ ∧ θ ↔ χ ∧ θ

Proof

Step Hyp Ref Expression
1 anbid.1 ⊢ φ → ψ ↔ χ
2 1 a1d ⊢ φ → θ → ψ ↔ χ
3 2 pm5.32rd ⊢ φ → ψ ∧ θ ↔ χ ∧ θ