static int[] intArray_minus(int[] array, int x) {
  if (x == 0 || empty(array)) ret array;
  int n = array.length;
  int[] b = new[n];
  for i to n:
    b[i] = array[i]-x;
  ret b;
}

static int[] intArray_minus(int x, int[] array) {
  ret intArray_minus(array, x);
}

static int[] intArray_minus(int[] array1, int[] array2) {
  int n = l(array1);
  if (l(array2) != n) fail("Need same size");
  if (n == 0) ret array1;
  int[] b = new[n];
  for i to n:
    b[i] = array1[i]-array2[i];
  ret b;
}