Metamath Proof Explorer

Theorem anbi1i

Description: Introduce a right conjunct to both sides of a logical equivalence. (Contributed by NM, 12-Mar-1993) (Proof shortened by Wolf Lammen, 16-Nov-2013)

Ref Expression
Hypothesis anbi.1 φ ψ
Assertion anbi1i φ χ ψ χ


Step Hyp Ref Expression
1 anbi.1 φ ψ
2 1 a1i χ φ ψ
3 2 pm5.32ri φ χ ψ χ