Theorem spvwOLD

Description: Obsolete version of spvw as of 20-Oct-2023. (Contributed by NM, 10-Apr-2017) (Proof shortened by Wolf Lammen, 4-Dec-2017) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Assertion	spvwOLD	$$⊢\forall x\phi \to \phi$$

Proof

Step	Hyp	Ref	Expression
1		19.3v	$$⊢\forall x\phi \leftrightarrow \phi$$
2	1	biimpi	$$⊢\forall x\phi \to \phi$$