reset;

option solver cplex;                            # solver

param n := 5;									# size of matrix A
param a {i in 1..n,j in 1..n} := Uniform(-1,1);	# coefficients of A

var x {i in 1..n,j in 1..n};					# variables for inverse A^-1

#minimize   LP: x[1,1]; 						# objective (not needed)

subject to NB {i in 1..n,j in 1..n}:			# identity equations (AX=I)
   sum{k in 1..n} a[i,k]*x[k,j] = if i=j then 1 else 0;  

solve;	   										# solution

display x;	   									# output