Metamath Proof Explorer


Theorem cshweqdifid

Description: If cyclically shifting a word by two positions results in the same word, cyclically shifting the word by the difference of these two positions results in the original word itself. (Contributed by AV, 21-Apr-2018) (Revised by AV, 7-Jun-2018) (Revised by AV, 1-Nov-2018)

Ref Expression
Assertion cshweqdifid W Word V N M W cyclShift N = W cyclShift M W cyclShift M N = W

Proof

Step Hyp Ref Expression
1 id W Word V W Word V
2 1 ancli W Word V W Word V W Word V
3 2 anim1i W Word V N M W Word V W Word V N M
4 3 3impb W Word V N M W Word V W Word V N M
5 cshweqdif2 W Word V W Word V N M W cyclShift N = W cyclShift M W cyclShift M N = W
6 4 5 syl W Word V N M W cyclShift N = W cyclShift M W cyclShift M N = W