BinarySearch := proc( A, value )
        description "iterative binary search";
        local low, high;

        low, high := ( lowerbound, upperbound )( A );
        while low <= high do
                local mid := iquo( low + high, 2 );
                if A[ mid ] > value then
                        high := mid - 1
                elif A[ mid ] < value then
                        low := mid + 1
                else
                        return mid
                end if
        end do;
        FAIL
end proc: