SUB consolidate (s$)
    DIM sets$(100)
    n = 0
    FOR i = 1 TO LEN(s$)
        IF MID$(s$, i, 1) = "," THEN
            n = n + 1
        ELSE
            sets$(n) = sets$(n) + MID$(s$, i, 1)
        END IF
    NEXT i

    FOR i = 0 TO n
        p = i
        ts$ = ""
        FOR j = i TO 0 STEP -1
            IF ts$ = "" THEN
                p = j
            END IF
            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$ = ts$ + MID$(sets$(p), k, 1)
                    END IF
                END IF
            NEXT k
            IF LEN(ts$) < LEN(sets$(p)) THEN
                IF j > 0 THEN
                    sets$(j - 1) = sets$(j - 1) + ts$
                    sets$(p) = "-"
                    ts$ = ""
                END IF
            ELSE
                p = i
            END IF
        NEXT j
    NEXT i

    temp$ = sets$(0)
    FOR i = 1 TO n
        temp$ = temp$ + "," + sets$(i)
    NEXT i

    PRINT s$; " = "; temp$
END SUB

DIM test$(3)
test$(0) = "AB"
test$(1) = "AB,CD"
test$(2) = "AB,CD,DB"
test$(3) = "HIK,AB,CD,DB,FGH"
FOR t = 0 TO 3
    CALL consolidate(test$(t))
NEXT t