Theorem iidn3

Description: idn3 without virtual deduction connectives. Special theorem needed for the Virtual Deduction translation tool. (Contributed by Alan Sare, 23-Jul-2011) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Assertion	iidn3	$$⊢\phi \to \left(\psi \to \left(\chi \to \chi \right)\right)$$

Proof

Step	Hyp	Ref	Expression
1		id	$$⊢\chi \to \chi$$
2	1	2a1i	$$⊢\phi \to \left(\psi \to \left(\chi \to \chi \right)\right)$$