Theorem mpdd 41

Description: A nested modus ponens deduction. (Contributed by NM, 12-Dec-2004.)

Hypotheses

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

Assertion

Ref	Expression
mpdd	⊢ (𝜑 → (𝜓 → 𝜃))

Proof of Theorem mpdd

Step	Hyp	Ref	Expression
1		mpdd.1	. 2 ⊢ (𝜑 → (𝜓 → 𝜒))
2		mpdd.2	. . 3 ⊢ (𝜑 → (𝜓 → (𝜒 → 𝜃)))
3	2	a2d 26	. 2 ⊢ (𝜑 → ((𝜓 → 𝜒) → (𝜓 → 𝜃)))
4	1, 3	mpd 13	1 ⊢ (𝜑 → (𝜓 → 𝜃))

Syntax hints:   → wi 4

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

This theorem is referenced by:  mpid  42  mpdi  43  syld  45  syl6c  66  mpteqb  5511  oprabid  5803  nnmordi  6412  nnmord  6413  brecop  6519  findcard2  6783  findcard2s  6784  ordiso2  6920  zindd  9169  cau3lem  10886  climcau  11116  dvdsabseq  11545  metrest  12675