Theorem imim12d 73

Description: Deduction combining antecedents and consequents. (Contributed by NM, 7-Aug-1994.) (Proof shortened by O'Cat, 30-Oct-2011.)

Hypotheses

Ref	Expression
imim12d.1	⊢ (𝜑 → (𝜓 → 𝜒))
imim12d.2	⊢ (𝜑 → (𝜃 → 𝜏))

Assertion

Ref	Expression
imim12d	⊢ (𝜑 → ((𝜒 → 𝜃) → (𝜓 → 𝜏)))

Proof of Theorem imim12d

Step	Hyp	Ref	Expression
1		imim12d.1	. 2 ⊢ (𝜑 → (𝜓 → 𝜒))
2		imim12d.2	. . 3 ⊢ (𝜑 → (𝜃 → 𝜏))
3	2	imim2d 53	. 2 ⊢ (𝜑 → ((𝜒 → 𝜃) → (𝜒 → 𝜏)))
4	1, 3	syl5d 67	1 ⊢ (𝜑 → ((𝜒 → 𝜃) → (𝜓 → 𝜏)))

Syntax hints:   → wi 4

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

This theorem is referenced by:  imim1d  74  equveli  1682  hbsb4t  1930  mo23  1982  rspcimdv  2702  r19.29uz  9878  setindis  10762  bdsetindis  10764  bj-findis  10774