Theorem dfvd1impr

Description: Right-to-left part of definition of virtual deduction. (Contributed by Alan Sare, 21-Apr-2011) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Assertion	dfvd1impr	⊢ ( ( 𝜑 → 𝜓 ) → (    𝜑    ▶    𝜓    ) )

Proof

Step	Hyp	Ref	Expression
1		df-vd1	⊢ ( (    𝜑    ▶    𝜓    ) ↔ ( 𝜑 → 𝜓 ) )
2	1	biimpri	⊢ ( ( 𝜑 → 𝜓 ) → (    𝜑    ▶    𝜓    ) )