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	⊢ ( 𝜑 → 𝜓 )
Assertion	19.8ad	⊢ ( 𝜑 → ∃ 𝑥 𝜓 )

Proof

Step	Hyp	Ref	Expression
1		19.8ad.1	⊢ ( 𝜑 → 𝜓 )
2		19.8a	⊢ ( 𝜓 → ∃ 𝑥 𝜓 )
3	1 2	syl	⊢ ( 𝜑 → ∃ 𝑥 𝜓 )