Theorem syl5d 68

Description: A nested syllogism deduction. (Contributed by NM, 5-Aug-1993.) (Proof shortened by Josh Purinton, 29-Dec-2000.) (Proof shortened by O'Cat, 2-Feb-2006.)

Hypotheses

Ref	Expression
syl5d.1	⊢ (𝜑 → (𝜓 → 𝜒))
syl5d.2	⊢ (𝜑 → (𝜃 → (𝜒 → 𝜏)))

Assertion

Ref	Expression
syl5d	⊢ (𝜑 → (𝜃 → (𝜓 → 𝜏)))

Proof of Theorem syl5d

Step	Hyp	Ref	Expression
1		syl5d.1	. . 3 ⊢ (𝜑 → (𝜓 → 𝜒))
2	1	a1d 22	. 2 ⊢ (𝜑 → (𝜃 → (𝜓 → 𝜒)))
3		syl5d.2	. 2 ⊢ (𝜑 → (𝜃 → (𝜒 → 𝜏)))
4	2, 3	syldd 67	1 ⊢ (𝜑 → (𝜃 → (𝜓 → 𝜏)))

Syntax hints:   → wi 4

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

This theorem is referenced by:  syl7  69  syl9  72  imim12d  74  jaddc  859  pm4.79dc  898