Theorem 19.8ad

Description: If a wff is true, it is true for at least one instance. Deduction form of 19.8a . (Contributed by DAW, 13-Feb-2017)

	Ref	Expression
Hypothesis	19.8ad.1	$$⊢\phi \to \psi$$
Assertion	19.8ad	$$⊢\phi \to \exists x\psi$$

Proof

Step	Hyp	Ref	Expression
1		19.8ad.1	$$⊢\phi \to \psi$$
2		19.8a	$$⊢\psi \to \exists x\psi$$
3	1 2	syl	$$⊢\phi \to \exists x\psi$$