This is Coxeter version 3.1.
Enter help if you need assistance, carriage return to start the program.

coxeter : 
type : 
rank : coxeter : enter your element (finish with a carriage return) :
213
coxeter : enter your element (finish with a carriage return) :
h[0] = 1  h[1] = 3  h[2] = 3  h[3] = 1  

size : 8

coxeter : coxeter :