01
01
021
2103
1230
 composing 021 and 021 = 012
 composing 2103 and 2103 = 0123
inverse of 021 = 021
 checking 012
inverse of 2103 = 2103
 checking 0123
inverse of 1230 = 3012
 checking 0123
 identity  :0
 ridentity :0

 identity  :01
 ridentity :10

 identity  :012
 ridentity :210

 identity  :0123
 ridentity :3210

 identity  :01234
 ridentity :43210