Theorem syl9r 73

Description: A nested syllogism inference with different antecedents. (Contributed by NM, 5-Aug-1993.)

Hypotheses

Ref	Expression
syl9r.1	⊢ (𝜑 → (𝜓 → 𝜒))
syl9r.2	⊢ (𝜃 → (𝜒 → 𝜏))

Assertion

Ref	Expression
syl9r	⊢ (𝜃 → (𝜑 → (𝜓 → 𝜏)))

Proof of Theorem syl9r

Step	Hyp	Ref	Expression
1		syl9r.1	. . 3 ⊢ (𝜑 → (𝜓 → 𝜒))
2		syl9r.2	. . 3 ⊢ (𝜃 → (𝜒 → 𝜏))
3	1, 2	syl9 72	. 2 ⊢ (𝜑 → (𝜃 → (𝜓 → 𝜏)))
4	3	com12 30	1 ⊢ (𝜃 → (𝜑 → (𝜓 → 𝜏)))

This proof depends on syntax axioms:   → wi 4

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7

This theorem is used by:  sylan9r  414  const  864  pm2.85dc  917  looinvdc  927  pclem6  1423  nfimd  1638  19.23t  1729  fununi  5449  dfimafn  5751  funimass3  5825  dfimafnf  5955  nnsub  9343  bj-con1st  16779