Attempt at making a Merge Sort in pseudocode

Mergsort_In_pseudocode

A[] = { 28, 39, 48, 27, 9, 88, 11, 4, 7} // Global variable, disregard bad programming practices

Function Split(int low, int hi){ // Adding brackets because not only am I used to java, it should help readability
  if (hi - low) < 2 then
    return array of elements from [low, hi]
  mid = (hi + low) / 2
  B[] = split(low, mid-1) // Either I do mid-1 or mid+1, the results seem the same
  C[] = split(mid, hi) // Same problems as above
  D[] = Merge(B[], C[])
  return D[]
End Function

Function Merge(B[], C[]) // I use two arrays because I figured it'd be the easiest to work with. 
  int PosB = 0, PosC = 0, PosMax = (b.length + c.length) -1 // PosB and PosC keep track of the positions in the cells of B and C
  // respectively. PosMax keeps track of the max cell that E[] (declared below) should have as well as the max number for the for loop
  E[num] // Declare and iniatialize an array that is supposed to hold the combined values of B and C, sorted.
  for i = 0 to num
    if PosC >= c.length or B[PosB] < C[PosC] // Checks if C[] already has added everything it has to E[] and if so, proceeds to add the
    // supposedly already sorted array B[]'s elements to E[]. Emphasis on "supposedly". A problem here is it does not check for if PosB
    // is out of bounds, which is a huge problem with primitive arrays. Also checks if the current element in C is greater than the
    // current element in B, and if so, add the element in B and increment.
      E[i] = B[PosB]
      PosB += 1 // Does not check whether or not PosB is at the end, gotta figure a way to check
    Else
      E[i] = C[PosC]
      PosC += 1
    End If
  Next
End Function