Theorem ee020 44671

Description: e020 44670 without virtual deductions. (Contributed by Alan Sare, 13-Jul-2011.) (Proof modification is discouraged.) (New usage is discouraged.)

Hypotheses

Ref	Expression
ee020.1	⊢ 𝜑
ee020.2	⊢ (𝜓 → (𝜒 → 𝜃))
ee020.3	⊢ 𝜏
ee020.4	⊢ (𝜑 → (𝜃 → (𝜏 → 𝜂)))

Assertion

Ref	Expression
ee020	⊢ (𝜓 → (𝜒 → 𝜂))

Proof of Theorem ee020

Step	Hyp	Ref	Expression
1		ee020.1	. . . 4 ⊢ 𝜑
2	1	a1i 11	. . 3 ⊢ (𝜒 → 𝜑)
3	2	a1i 11	. 2 ⊢ (𝜓 → (𝜒 → 𝜑))
4		ee020.2	. 2 ⊢ (𝜓 → (𝜒 → 𝜃))
5		ee020.3	. . . 4 ⊢ 𝜏
6	5	a1i 11	. . 3 ⊢ (𝜒 → 𝜏)
7	6	a1i 11	. 2 ⊢ (𝜓 → (𝜒 → 𝜏))
8		ee020.4	. 2 ⊢ (𝜑 → (𝜃 → (𝜏 → 𝜂)))
9	3, 4, 7, 8	ee222 44527	1 ⊢ (𝜓 → (𝜒 → 𝜂))

Syntax hints:   → wi 4

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 207  df-an 396

This theorem is referenced by: (None)