!ASIS Issue #089
!topic What is the same physical CU (compilation unit)
!reference  ASIS 95-10.18
!from  Sergey Rybin 98-01-19
!keywords compilation unit time stamp Is_Identical
!discussion

Clause 10.17 (function Is_Equal) and Clause 10.18 (function
Is_Identical) should not discriminate based on compilation time stamp.
Instead, they should discriminate on using program text.

!resolution  Accept
!date 98-03-26
!Notes

Change the parenthetical phrase on both 10.17 (Is_Equal) and 10.18
(Is_Identical) from:

        ("The same physical compilation unit" have the same name
        and the same compilation time stamp.)

to:

        ("The same physical compilation unit" have the same version,
        as defined by Reference Manual E.3(5) and the same program
        text.)

Justification:

1. Having the same program text implies having the same name.
2. Having the same version does not imply having the same program text.
3. If we would like to have Is_Equial as a test, that two units have the
   same semantic, we need the notion of a unit version.
4. RM 95 E.3 (5) also implies, that "details are implementation-defined".