The Radix Point Symbol routine returns the system's radix point
    symbol. This symbol is used inside a digit string to separate
    the integer part from the fraction part. This routine works by
    attempting to translate the logical name SYS$RADIX_POINT as a
    process, group, or system logical name.

    Format

      LIB$RADIX_POINT  radix-point-string [,resultant-length]