Description: Transitivity law for congruence. Theorem 2.3 of Schwabhauser p. 27. (Contributed by Scott Fenton, 24-Sep-2013)
Ref | Expression | ||
---|---|---|---|
Assertion | cgrtr | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simp1 | |
|
2 | simp23 | |
|
3 | simp31 | |
|
4 | simp21 | |
|
5 | simp22 | |
|
6 | simp32 | |
|
7 | simp33 | |
|
8 | simprl | |
|
9 | 1 4 5 2 3 8 | cgrcomand | |
10 | simprr | |
|
11 | 1 2 3 4 5 6 7 9 10 | cgrtr4and | |
12 | 11 | ex | |