Theorem syl6ci 69

Description: A syllogism inference combined with contraction. (Contributed by Alan Sare, 18-Mar-2012.)

Hypotheses

Ref	Expression
syl6ci.1	⊢ (𝜑 → (𝜓 → 𝜒))
syl6ci.2	⊢ (𝜑 → 𝜃)
syl6ci.3	⊢ (𝜒 → (𝜃 → 𝜏))

Assertion

Ref	Expression
syl6ci	⊢ (𝜑 → (𝜓 → 𝜏))

Proof of Theorem syl6ci

Step	Hyp	Ref	Expression
1		syl6ci.1	. 2 ⊢ (𝜑 → (𝜓 → 𝜒))
2		syl6ci.2	. . 3 ⊢ (𝜑 → 𝜃)
3	2	a1d 25	. 2 ⊢ (𝜑 → (𝜓 → 𝜃))
4		syl6ci.3	. 2 ⊢ (𝜒 → (𝜃 → 𝜏))
5	1, 3, 4	syl6c 68	1 ⊢ (𝜑 → (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:  ordelord  5662  f1dmex  7029  omeulem2  7550  2pwuninel  8000  isumrpcl  14414  kqfvima  21343  caubl  22914  frgrawopreglem2  26572  soseq  30995  btwnconn1lem12  31375  sbcim2g  37769  ee21an  37980  nbupgr  40566  nbumgrvtx  40568  umgr2adedgspth  41155