Metamath Proof Explorer


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 φ ψ χ χ

Proof

Step Hyp Ref Expression
1 id χ χ
2 1 2a1i φ ψ χ χ