Theorem syl11

Description: A syllogism inference. Commuted form of an instance of syl . (Contributed by BJ, 25-Oct-2021)

	Ref	Expression
Hypotheses	syl11.1	$$⊢\phi \to \left(\psi \to \chi \right)$$
	syl11.2	$$⊢\theta \to \phi$$
Assertion	syl11	$$⊢\psi \to \left(\theta \to \chi \right)$$

Proof

Step	Hyp	Ref	Expression
1		syl11.1	$$⊢\phi \to \left(\psi \to \chi \right)$$
2		syl11.2	$$⊢\theta \to \phi$$
3	2 1	syl	$$⊢\theta \to \left(\psi \to \chi \right)$$
4	3	com12	$$⊢\psi \to \left(\theta \to \chi \right)$$