Theorem 4syl 18

Description: Inference chaining three syllogisms. The use of this theorem is marked "discouraged" because it can cause the "minimize" command to have very long run times. However, feel free to use "minimize 4syl /override" if you wish. (Contributed by BJ, 14-Jul-2018.) (New usage is discouraged.)

Hypotheses

Ref	Expression
4syl.1	⊢ (𝜑 → 𝜓)
4syl.2	⊢ (𝜓 → 𝜒)
4syl.3	⊢ (𝜒 → 𝜃)
4syl.4	⊢ (𝜃 → 𝜏)

Assertion

Ref	Expression
4syl	⊢ (𝜑 → 𝜏)

Proof of Theorem 4syl

Step	Hyp	Ref	Expression
1		4syl.1	. . 3 ⊢ (𝜑 → 𝜓)
2		4syl.2	. . 3 ⊢ (𝜓 → 𝜒)
3		4syl.3	. . 3 ⊢ (𝜒 → 𝜃)
4	1, 2, 3	3syl 17	. 2 ⊢ (𝜑 → 𝜃)
5		4syl.4	. 2 ⊢ (𝜃 → 𝜏)
6	4, 5	syl 14	1 ⊢ (𝜑 → 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:  f1ocnvfvrneq  5982  fcof1o  5989  isoselem  6020  isose  6021  tposss  6511  smoiso  6567  fzssp1  10456  fzosplitsnm1  10610  fzofzp1  10628  fzostep1  10639  bcm1k  11181  pfxccatpfx2  11492  climuni  12042  serf0  12101  fsumparts  12220  hashiun  12228  oddprm  13021  znzrh2  14964  znf1o  14969  znidom  14975  hmeores  15399  gausslemma2dlem0c  16153  gausslemma2dlem0e  16155  gausslemma2dlem1a  16160  eupthvdres  16699