Function Consolidate(s As String) As String
    Dim As Integer i, j, k, p, n, pio, fin
    Dim As String ts, sets(0 To 100), temp

    ' Split the string into substrings
    pio = 1
    n = 0
    For i = 1 To Len(s)
        If Mid(s, i, 1) = "," Then
            fin = i - 1
            sets(n) = Mid(s, pio, fin - pio + 1)
            pio = i + 1
            n += 1
        End If
    Next i
    sets(n) = Mid(s, pio, Len(s) - pio + 1)

    ' Main logic
    For i = 0 To n
        p = i
        ts = ""
        For j = i To 0 Step -1
            If ts = "" Then p = j
            ts = ""
            For k = 1 To Len(sets(p))
                If j > 0 Then
                    If Instr(sets(j-1), Mid(sets(p), k, 1)) = 0 Then ts += Mid(sets(p), k, 1)
                End If
            Next k
            If Len(ts) < Len(sets(p)) Then
                If j > 0 Then
                    sets(j-1) += ts
                    sets(p) = "-"
                    ts = ""
                End If
            Else
                p = i
            End If
        Next j
    Next i

    ' Join the substrings into a string
    temp = sets(0)
    For i = 1 To n
        temp += "," + sets(i)
    Next i

    Return s + " = " + temp
End Function

Dim As String test(3) = {"AB", "AB,CD", "AB,CD,DB", "HIK,AB,CD,DB,FGH"}
For t As Integer = Lbound(test) To Ubound(test)
    Print Consolidate(test(t))
Next t

Sleep