PROCsolve24("1234")
      PROCsolve24("6789")
      PROCsolve24("1127")
      PROCsolve24("5566")
      END

      DEF PROCsolve24(s$)
      LOCAL F%, I%, J%, K%, L%, P%, T%, X$, o$(), p$(), t$()
      DIM o$(4), p$(24,4), t$(11)
      o$() = "", "+", "-", "*", "/"
      RESTORE
      FOR T% = 1 TO 11
        READ t$(T%)
      NEXT
      DATA "abcdefg", "(abc)defg", "ab(cde)fg", "abcd(efg)", "(abc)d(efg)", "(abcde)fg"
      DATA "ab(cdefg)", "((abc)de)fg", "(ab(cde))fg", "ab((cde)fg)", "ab(cd(efg))"

      FOR I% = 1 TO 4
        FOR J% = 1 TO 4
          FOR K% = 1 TO 4
            FOR L% = 1 TO 4
              IF I%<>J% IF J%<>K% IF K%<>L% IF I%<>K% IF J%<>L% IF I%<>L% THEN
                P% += 1
                p$(P%,1) = MID$(s$,I%,1)
                p$(P%,2) = MID$(s$,J%,1)
                p$(P%,3) = MID$(s$,K%,1)
                p$(P%,4) = MID$(s$,L%,1)
              ENDIF
            NEXT
          NEXT
        NEXT
      NEXT

      FOR I% = 1 TO 4
        FOR J% = 1 TO 4
          FOR K% = 1 TO 4
            FOR T% = 1 TO 11
              FOR P% = 1 TO 24
                X$ = t$(T%)
                MID$(X$, INSTR(X$,"a"), 1) = p$(P%,1)
                MID$(X$, INSTR(X$,"b"), 1) = o$(I%)
                MID$(X$, INSTR(X$,"c"), 1) = p$(P%,2)
                MID$(X$, INSTR(X$,"d"), 1) = o$(J%)
                MID$(X$, INSTR(X$,"e"), 1) = p$(P%,3)
                MID$(X$, INSTR(X$,"f"), 1) = o$(K%)
                MID$(X$, INSTR(X$,"g"), 1) = p$(P%,4)
                F% = TRUE : ON ERROR LOCAL F% = FALSE
                IF F% IF EVAL(X$) = 24 THEN PRINT X$ : EXIT FOR I%
                RESTORE ERROR
              NEXT
            NEXT
          NEXT
        NEXT
      NEXT
      IF I% > 4 PRINT "No solution found"
      ENDPROC