Theorem anbi1d

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.)

Hypothesis
anbid.1
\( \vdash \varphi \rightarrow (\psi \leftrightarrow \chi) \)
Conclusion
\( \vdash \varphi \rightarrow (\psi \wedge \theta \leftrightarrow \chi \wedge \theta) \)
Proof
anbid.1
a1d _
pm5.32rd _