Theorem el3v1

Description: New way ( elv , and the theorems beginning with "el2v" or "el3v") to shorten some proofs. (Contributed by Peter Mazsa, 16-Oct-2020)

	Ref	Expression
Hypothesis	el3v1.1	$$⊢\left(x\in \mathrm{V}\wedge \psi \wedge \chi \right)\to \theta$$
Assertion	el3v1	$$⊢\left(\psi \wedge \chi \right)\to \theta$$

Proof

Step	Hyp	Ref	Expression
1		el3v1.1	$$⊢\left(x\in \mathrm{V}\wedge \psi \wedge \chi \right)\to \theta$$
2		vex	$$⊢x\in \mathrm{V}$$
3	2 1	mp3an1	$$⊢\left(\psi \wedge \chi \right)\to \theta$$