Theorem idn3 39663

Description: Virtual deduction identity rule for three virtual hypotheses. (Contributed by Alan Sare, 11-Jun-2011.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
idn3	⊢ (   𝜑   ,   𝜓   ,   𝜒   ▶   𝜒   )

Proof of Theorem idn3

Step	Hyp	Ref	Expression
1		idd 24	. . 3 ⊢ (𝜓 → (𝜒 → 𝜒))
2	1	a1i 11	. 2 ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜒)))
3	2	dfvd3ir 39632	1 ⊢ (   𝜑   ,   𝜓   ,   𝜒   ▶   𝜒   )

Syntax hints:   → wi 4  (   wvd3 39626

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 199  df-an 387  df-3an 1113  df-vd3 39629

This theorem is referenced by:  suctrALT2VD  39885  en3lplem2VD  39893  exbirVD  39902  exbiriVD  39903  rspsbc2VD  39904  tratrbVD  39910  ssralv2VD  39915  imbi12VD  39922  imbi13VD  39923  truniALTVD  39927  trintALTVD  39929  onfrALTlem2VD  39938