Theorem ee121 42132

Description: e121 42283 without virtual deductions. (Contributed by Alan Sare, 13-Jul-2011.) (Proof modification is discouraged.) (New usage is discouraged.)

Hypotheses

Ref	Expression
ee121.1	⊢ (𝜑 → 𝜓)
ee121.2	⊢ (𝜑 → (𝜒 → 𝜃))
ee121.3	⊢ (𝜑 → 𝜏)
ee121.4	⊢ (𝜓 → (𝜃 → (𝜏 → 𝜂)))

Assertion

Ref	Expression
ee121	⊢ (𝜑 → (𝜒 → 𝜂))

Proof of Theorem ee121

Step	Hyp	Ref	Expression
1		ee121.1	. . 3 ⊢ (𝜑 → 𝜓)
2	1	a1d 25	. 2 ⊢ (𝜑 → (𝜒 → 𝜓))
3		ee121.2	. 2 ⊢ (𝜑 → (𝜒 → 𝜃))
4		ee121.3	. . 3 ⊢ (𝜑 → 𝜏)
5	4	a1d 25	. 2 ⊢ (𝜑 → (𝜒 → 𝜏))
6		ee121.4	. 2 ⊢ (𝜓 → (𝜃 → (𝜏 → 𝜂)))
7	2, 3, 5, 6	ee222 42129	1 ⊢ (𝜑 → (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 206  df-an 397

This theorem is referenced by:  tratrb  42163