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From: =?utf-8?Q?Yannick_Duch=C3=AAne_=28Hibou57?=
 =?utf-8?Q?=29?=
 <yannick_duchene@yahoo.fr>
Newsgroups: comp.lang.ada
Subject: Re: Lost in translation (with SPARK user rules)
Date: Thu, 27 May 2010 13:32:15 +0200
Organization: Ada At Home
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Date: 2010-05-27T13:32:15+02:00
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Le Thu, 27 May 2010 12:55:04 +0200, Yannick Duch=C3=AAne (Hibou57)  =

<yannick_duchene@yahoo.fr> a =C3=A9crit:
> And Simplifier fails to prove Check #3 ; an excerpt of the *.SIV file =
 =

> shows why (conclusion associated to Check #3):
>
>     C1:    bit__and(v, 1) =3D 0 or bit__and(v, 1) =3D 1 .

Ok, found. I was not correct with the way to require the type to be  =

integer as done in

    my_set(1): (X=3D0) or (X=3D1) may_be_deduced_from [ integer(X), X>=3D=
0, X<=3D1  =

].

It has to be

    my_set(1): (X=3D0) or (X=3D1) may_be_deduced_from [  =

goal(checktype(X,integer)), X>=3D0, X<=3D1 ].

I've check that

    my_set(1): (X=3D0) or (X=3D1) may_be_deduced_from [ goal(integer(X))=
, X>=3D0,  =

X<=3D1 ].

does not work, which lead to another question : what is the difference  =

between the two predicates =E2=80=9Cinteger(X)=E2=80=9D and =E2=80=9Cche=
cktype(X,integer)=E2=80=9D ? The  =

documentation is not clear to me about it. About =E2=80=9Cchecktype(EXPR=
ESSION,  =

TYPE_IDENTIFIER)=E2=80=9D, it says =E2=80=9CThis predicate may be used t=
o check that an  =

expression is of an appropriate type=E2=80=9D and about =E2=80=9Cinteger=
(EXPRESSION)=E2=80=9D is  =

says This built-in Prolog predicate succeeds if and only if its argument=
  =

is instantiated to an integer. So what's the difference between  =

=E2=80=9Cgoal(integer(X))=E2=80=9D and =E2=80=9Cgoal(checktype(X,integer=
))=E2=80=9D. Does the latter  =

refers to root type as defined in source and the other to something else=
 ?  =

(so what?)

Another strange thing is that the file NUMINEQS.RUL does not contains an=
y  =

predicate stating arguments have to be integers and there is just a  =

comment in heading, nothing in rules about it.

-- =

There is even better than a pragma Assert: a SPARK --# check.
--# check C and WhoKnowWhat and YouKnowWho;
--# assert Ada;
--  i.e. forget about previous premises which leads to conclusion
--  and start with new conclusion as premise.