Frama-C-discuss mailing list archives

This page gathers the archives of the old Frama-C-discuss archives, that was hosted by Inria's gforge before its demise at the end of 2020. To search for mails newer than September 2020, please visit the page of the new mailing list on Renater.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Frama-c-discuss] Unability to verify an arithmetic assertion disapears in a reduced but similar test case

Hello,

Le jeu 19 mar 2009 09:40:47 CET,
David MENTRE <dmentre at linux-france.org> a ?crit :

> 
> I realized that more or less by trial and error. Is this written
> somewhere in Jessie documentation? I have probably read it but
> overlooked it.

There are a few words about loop invariants in section 2.1 of the
manual, but that could be more precise indeed.

> 
> By the way, I have seen that some "global" knowledge is also kept
> (assertions about global variables? function pre-condition?). Is this
> correct? Is this described somewhere?

I'm unsure what you mean by "global knowledge". assertion on variables
(and regions) that are not modified by the loop will still hold, but
that's all.

> I have a side question: I usually write \forall assertions with an
> int: "\forall int i; [...]". You write your assertion with "integer",
> "\forall integer i; [...]". Is there any difference? Any reason to
> prefer one over the other?

Technically, there are only integers in the logic, int is only a
shortcut to say 'I have an integer and it is between MIN_INT and
MAX_INT'. It exists mainly to be able to lift C lval in the logic, but
purely ACSL values should use the primitive type directly.

Best regards,
-- 
E tutto per oggi, a la prossima volta.
Virgile