 
 
 
Rref is the inert form of rref.
Rref returns rref without
evaluation. 
It is used in conjunction with mod in Maple syntax mode to 
find the row reduction to echelon form 
of a matrix with coefficients in ℤ/pℤ (see 
also 5.61.3).
Example, solve in ℤ/13ℤ
| ⎧ ⎨ ⎩ | 
 | 
Input in Xcas mode :
Output :
you need to eval(ans()) to get :
 
and conclude that x=3%13 and y=3%13.
Input in Maple mode :
Output :
 
 
