Theorem bj-19.21bit

Description: Closed form of 19.21bi . (Contributed by BJ, 20-Oct-2019)

	Ref	Expression
Assertion	bj-19.21bit	$$⊢\left(\phi \to \forall x\psi \right)\to \left(\phi \to \psi \right)$$

Proof

Step	Hyp	Ref	Expression
1		sp	$$⊢\forall x\psi \to \psi$$
2	1	imim2i	$$⊢\left(\phi \to \forall x\psi \right)\to \left(\phi \to \psi \right)$$