Metamath Proof Explorer


Theorem cgr3com

Description: Commutativity law for three-place congruence. (Contributed by Scott Fenton, 5-Oct-2013)

Ref Expression
Assertion cgr3com N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N E 𝔼 N F 𝔼 N A B C Cgr3 D E F D E F Cgr3 A B C

Proof

Step Hyp Ref Expression
1 id N N
2 3simpa A 𝔼 N B 𝔼 N C 𝔼 N A 𝔼 N B 𝔼 N
3 3simpa D 𝔼 N E 𝔼 N F 𝔼 N D 𝔼 N E 𝔼 N
4 cgrcom N A 𝔼 N B 𝔼 N D 𝔼 N E 𝔼 N A B Cgr D E D E Cgr A B
5 1 2 3 4 syl3an N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N E 𝔼 N F 𝔼 N A B Cgr D E D E Cgr A B
6 3simpb A 𝔼 N B 𝔼 N C 𝔼 N A 𝔼 N C 𝔼 N
7 3simpb D 𝔼 N E 𝔼 N F 𝔼 N D 𝔼 N F 𝔼 N
8 cgrcom N A 𝔼 N C 𝔼 N D 𝔼 N F 𝔼 N A C Cgr D F D F Cgr A C
9 1 6 7 8 syl3an N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N E 𝔼 N F 𝔼 N A C Cgr D F D F Cgr A C
10 3simpc A 𝔼 N B 𝔼 N C 𝔼 N B 𝔼 N C 𝔼 N
11 3simpc D 𝔼 N E 𝔼 N F 𝔼 N E 𝔼 N F 𝔼 N
12 cgrcom N B 𝔼 N C 𝔼 N E 𝔼 N F 𝔼 N B C Cgr E F E F Cgr B C
13 1 10 11 12 syl3an N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N E 𝔼 N F 𝔼 N B C Cgr E F E F Cgr B C
14 5 9 13 3anbi123d N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N E 𝔼 N F 𝔼 N A B Cgr D E A C Cgr D F B C Cgr E F D E Cgr A B D F Cgr A C E F Cgr B C
15 brcgr3 N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N E 𝔼 N F 𝔼 N A B C Cgr3 D E F A B Cgr D E A C Cgr D F B C Cgr E F
16 brcgr3 N D 𝔼 N E 𝔼 N F 𝔼 N A 𝔼 N B 𝔼 N C 𝔼 N D E F Cgr3 A B C D E Cgr A B D F Cgr A C E F Cgr B C
17 16 3com23 N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N E 𝔼 N F 𝔼 N D E F Cgr3 A B C D E Cgr A B D F Cgr A C E F Cgr B C
18 14 15 17 3bitr4d N A 𝔼 N B 𝔼 N C 𝔼 N D 𝔼 N E 𝔼 N F 𝔼 N A B C Cgr3 D E F D E F Cgr3 A B C