func matrix add (matrix a, matrix b) {
  matrix c <2,2> = a + b; 
  print(c);
  return c;
}

func int main(){
  matrix a <2, 2>;
  matrix b <2, 2>;
  a = [1, 2; 3, 4];
  b = [0, 1; 1, 0];
  print(a);
  print(b);
  print(add(a, b));
  return 0;
}