Theorem wl-impchain-com-1.2

Description: This theorem is in fact a copy of wl-luk-com12 , and repeated here to demonstrate a simple proof scheme. The number '2' in the theorem name indicates that a chain of length 2 is modified.

See wl-impchain-com-1.x for more information how this proof is generated. (Contributed by Wolf Lammen, 7-Jul-2019) (New usage is discouraged.) (Proof modification is discouraged.)

	Ref	Expression
Hypothesis	wl-impchain-com.1.2.a	$$⊢\chi \to \left(\psi \to \phi \right)$$
Assertion	wl-impchain-com-1.2	$$⊢\psi \to \left(\chi \to \phi \right)$$

Proof

Step	Hyp	Ref	Expression
1		wl-impchain-com.1.2.a	$$⊢\chi \to \left(\psi \to \phi \right)$$
2	1	wl-impchain-com-1.1	$$⊢\chi \to \left(\psi \to \phi \right)$$
3		wl-luk-pm2.04	$$⊢\left(\chi \to \left(\psi \to \phi \right)\right)\to \left(\psi \to \left(\chi \to \phi \right)\right)$$
4	2 3	wl-impchain-mp-0	$$⊢\psi \to \left(\chi \to \phi \right)$$
5	4	wl-impchain-com-1.1	$$⊢\psi \to \left(\chi \to \phi \right)$$