The Free Event Flag routine frees a local event flag previously
    allocated by LIB$GET_EF or by LIB$RESERVE_EF. LIB$FREE_EF is the
    complement of LIB$GET_EF.

    Format

      LIB$FREE_EF  event-flag-number

1 - Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

2 - Argument

 event-flag-number

    OpenVMS usage:ef_number
    type:         longword integer (unsigned)
    access:       read only
    mechanism:    by reference

    Event flag number to be deallocated by LIB$FREE_EF. The event-
    flag-number argument is the address of a signed longword integer
    that contains the event flag number, which is the value allocated
    to the user by LIB$GET_EF or LIB$RESERVE_EF.