Theorem simplld

Deduction form of simpll, eliminating a double conjunct. (Contributed by Glauco Siliprandi, 11-Dec-2019.)

Hypothesis
simplld.1
\( \vdash \varphi \rightarrow \psi \wedge \chi \wedge \theta \)
Conclusion
\( \vdash \varphi \rightarrow \psi \)
Proof
simplld.1
\( \vdash \varphi \rightarrow \psi \wedge \chi \wedge \theta \)
simpld _
\( \vdash \varphi \rightarrow \psi \wedge \chi \)
simpld _