Theorem e020 42154

Description: A virtual deduction elimination rule. (Contributed by Alan Sare, 24-Jun-2011.) (Proof modification is discouraged.) (New usage is discouraged.)

Hypotheses

Ref	Expression
e020.1	⊢ 𝜑
e020.2	⊢ (   𝜓   ,   𝜒   ▶   𝜃   )
e020.3	⊢ 𝜏
e020.4	⊢ (𝜑 → (𝜃 → (𝜏 → 𝜂)))

Assertion

Ref	Expression
e020	⊢ (   𝜓   ,   𝜒   ▶   𝜂   )

Proof of Theorem e020

Step	Hyp	Ref	Expression
1		e020.1	. . 3 ⊢ 𝜑
2	1	vd02 42107	. 2 ⊢ (   𝜓   ,   𝜒   ▶   𝜑   )
3		e020.2	. 2 ⊢ (   𝜓   ,   𝜒   ▶   𝜃   )
4		e020.3	. . 3 ⊢ 𝜏
5	4	vd02 42107	. 2 ⊢ (   𝜓   ,   𝜒   ▶   𝜏   )
6		e020.4	. 2 ⊢ (𝜑 → (𝜃 → (𝜏 → 𝜂)))
7	2, 3, 5, 6	e222 42145	1 ⊢ (   𝜓   ,   𝜒   ▶   𝜂   )

Syntax hints:   → wi 4  (   wvd2 42086

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 206  df-an 396  df-vd2 42087

This theorem is referenced by: (None)