Metamath Proof Explorer


Theorem cgrtr

Description: Transitivity law for congruence. Theorem 2.3 of Schwabhauser p. 27. (Contributed by Scott Fenton, 24-Sep-2013)

Ref Expression
Assertion cgrtr NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NABCgrCDCDCgrEFABCgrEF

Proof

Step Hyp Ref Expression
1 simp1 NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NN
2 simp23 NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NC𝔼N
3 simp31 NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼ND𝔼N
4 simp21 NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NA𝔼N
5 simp22 NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NB𝔼N
6 simp32 NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NE𝔼N
7 simp33 NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NF𝔼N
8 simprl NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NABCgrCDCDCgrEFABCgrCD
9 1 4 5 2 3 8 cgrcomand NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NABCgrCDCDCgrEFCDCgrAB
10 simprr NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NABCgrCDCDCgrEFCDCgrEF
11 1 2 3 4 5 6 7 9 10 cgrtr4and NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NABCgrCDCDCgrEFABCgrEF
12 11 ex NA𝔼NB𝔼NC𝔼ND𝔼NE𝔼NF𝔼NABCgrCDCDCgrEFABCgrEF