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#82 Sum should be evaluated by Gosper's method, but isn't  ← ↑ →  #84 conjugate(c)

#83 Bug 5977 1::DMP([x],FRAC INT)::POLY FRAC INT ==> 0
  
last edited 10 years ago by test1

Edit detail for #83 Bug 5977 1::DMP([x],FRAC INT)::POLY FRAC INT ==> 0 revision 5 of 13
1 2 3 4 5 6 7 8 9 10 11 12 13
Editor: Bill Page
Time: 2008/05/21 07:52:50 GMT-7
Note: fixed? 
changed:
-William Sit <address@bogus.example.com> wrote:
-
-> Martin wrote:
-> 
-> Thanks for investigating further.
->  
-> > it might be that there is an error in mainVariable$SMP, but more likely, the
-> > bug is earlier in the history. mainVariable$SMP is called from coerce$POLY,
-> > interestingly without checking that the result of mainVariable might be
-> > "failed".
-> 
-> Shouldn't that mean coerce$POLY should be fixed to check the "failed" case?
William Sit <address@bogus.example.com> wrote::

 > Martin wrote:
 > 
 > Thanks for investigating further.
 >  
 > > it might be that there is an error in mainVariable$SMP, but more likely, the
 > > bug is earlier in the history. mainVariable$SMP is called from coerce$POLY,
 > > interestingly without checking that the result of mainVariable might be
 > > "failed".
 > 
 > Shouldn't that mean coerce$POLY should be fixed to check the "failed" case?

changed:
-not...
-
-> Which coerce$POLY is that?
-
-the coerce operation in the POLY domain.
-
-> > (66) -> 1::DMP([x],FRAC INT)::POLY FRAC INT
-> > 
-> >    coerce$POLY
-> >    mainVariable1$SMP
-> >    mainVariable3$SMP
-> >    mainVariable4$SMP
-> >  LISP output:
-> > 1
-> >    coerce4$POLY
-> >    1
-> >    coerce5$POLY
-> >    coerce6$POLY
-> >    (66)  0
-> >                           Type: Polynomial Fraction Integer
-
-> > Is there a way to find out what exactly the variable p in mainVariable
-> > contains?
-> > 
-> use p$Rep  ? or trace boot.
not::

 > Which coerce$POLY is that?

the coerce operation in the POLY domain::

 > > (66) -> 1::DMP([x],FRAC INT)::POLY FRAC INT
 > > 
 > >    coerce$POLY
 > >    mainVariable1$SMP
 > >    mainVariable3$SMP
 > >    mainVariable4$SMP
 > >  LISP output:
 > > 1
 > >    coerce4$POLY
 > >    1
 > >    coerce5$POLY
 > >    coerce6$POLY
 > >    (66)  0
 > >                           Type: Polynomial Fraction Integer
 
 > > Is there a way to find out what exactly the variable p in mainVariable
 > > contains?
 > > 
 > use p$Rep  ? or trace boot.

changed:
-the Algebra, not in the interpreter. 
-
-> Now p is declared in multpoly.spad as Union(R, VPoly).
-> So the code mainVariable p seems to be correct, but your debug info
-> 
-> > (65) -> 1::DMP([x],INT)::POLY INT
-> > 
-> >    coerce$POLY
-> >    mainVariable1$SMP
-> >    mainVariable3$SMP
-> >    mainVariable4$SMP
-> > 
-> >    >> System error:
-> >    Caught fatal error [memory may be damaged]
-> > 
-> > protected-symbol-warn called with (NIL)
-> 
-> suggests that when 1$DMP([x], INT) is passed on to coerce$(POLY INT) and then 
-> to
-> mainVariable$SMP as p, it is recognized as "case VPoly". So that must be where
-> the bug is, in coerce$(POLY INT).
the Algebra, not in the interpreter::

 > Now p is declared in multpoly.spad as Union(R, VPoly).
 > So the code mainVariable p seems to be correct, but your debug info
 > 
 > > (65) -> 1::DMP([x],INT)::POLY INT
 > > 
 > >    coerce$POLY
 > >    mainVariable1$SMP
 > >    mainVariable3$SMP
 > >    mainVariable4$SMP
 > > 
 > >    >> System error:
 > >    Caught fatal error [memory may be damaged]
 > > 
 > > protected-symbol-warn called with (NIL)
 > 
 > suggests that when 1$DMP([x], INT) is passed on to coerce$(POLY INT) and then 
 > to
 > mainVariable$SMP as p, it is recognized as "case VPoly". So that must be where
 > the bug is, in coerce$(POLY INT).

changed:
-(1) -> a:=1::DMP(['x],INT)
Problem::

 (1) -> a:=1::DMP(['x],INT)

changed:
-(2) -> a::POLY INT
 (2) -> a::POLY INT

changed:
-protected-symbol-warn called with (NIL)
-(2) -> variables(a)
 protected-symbol-warn called with (NIL)
 (2) -> variables(a)

changed:
-(3) -> a::INT::POLY INT
 (3) -> a::INT::POLY INT

changed:
-(4) -> 1::DMP([x],INT)::POLY INT
 (4) -> 1::DMP([x],INT)::POLY INT

changed:
-protected-symbol-warn called with (NIL)
-
-(5) -> 1::DMP([x],INT)::DMP([y],INT)
 protected-symbol-warn called with (NIL)

 (5) -> 1::DMP([x],INT)::DMP([y],INT)

changed:
-and 
-
-1::POLY INT :: DMP([x],INT) 
-x::DMP([x],INT)::POLY INT
-1::DMP([x,y],INT)::POLY INT 
-1::EXPR INT:: POLY INT 
-1::UP(x,INT)::POLY INT
- 
-and (surprise!) even
- 
-1::DMP([x],INT)::POLY FRAC INT
-
-all worked!
 and 

 1::POLY INT :: DMP([x],INT) 
 x::DMP([x],INT)::POLY INT
 1::DMP([x,y],INT)::POLY INT 
 1::EXPR INT:: POLY INT 
 1::UP(x,INT)::POLY INT
 
 and (surprise!) even
 
 1::DMP([x],INT)::POLY FRAC INT

 all worked!

Submitted by : (unknown) at: 2007-11-17T23:03:08-08:00 (16 years ago)
Name :
Axiom Version :
Category : Severity : Status :
Optional subject :  
Optional comment :

William Sit wrote: 

 > Martin wrote:
 > 
 > Thanks for investigating further.
 >  
 > > it might be that there is an error in mainVariable$SMP, but more likely, the
 > > bug is earlier in the history. mainVariable<img alt="LatexWiki Image" class="equation" src="images/5955511306385491609-18.0px.png" width="190" height="15"/>POLY,
 > > interestingly without checking that the result of mainVariable might be
 > > "failed".
 > 
 > Shouldn't that mean coerce$POLY should be fixed to check the "failed" case?

Sorry, my mistake. coerce$POLY checks itself whether there is a variable or not: 

 > Which coerce$POLY is that?

the coerce operation in the POLY domain: 

 > > (66) -> 1::DMP([x],FRAC INT)::POLY FRAC INT
 > > 
 > >    coerce$POLY
 > >    mainVariable1$SMP
 > >    mainVariable3$SMP
 > >    mainVariable4$SMP
 > >  LISP output:
 > > 1
 > >    coerce4$POLY
 > >    1
 > >    coerce5$POLY
 > >    coerce6$POLY
 > >    (66)  0
 > >                           Type: Polynomial Fraction Integer

 > > Is there a way to find out what exactly the variable p in mainVariable
 > > contains?
 > > 
 > use p$Rep  ? or trace boot.

I'm pretty sure that the coercion to from DMP to POLY fails, without signalling an error, just like you could always do a "pretend". This would also explain (66)

Note that it is not possible to coerce a DMP or a UP or anything the like to a POLY in compiled code! Unfortunately I don't know where these interpreter coercions are coded. In any case, I'm convinced that they should be coded in the Algebra, not in the interpreter: 

 > Now p is declared in multpoly.spad as Union(R, VPoly).
 > So the code mainVariable p seems to be correct, but your debug info
 > 
 > > (65) -> 1::DMP([x],INT)::POLY INT
 > > 
 > >    coerce$POLY
 > >    mainVariable1$SMP
 > >    mainVariable3$SMP
 > >    mainVariable4$SMP
 > > 
 > >    >> System error:
 > >    Caught fatal error [memory may be damaged]
 > > 
 > > protected-symbol-warn called with (NIL)
 > 
 > suggests that when 1<img alt="LatexWiki Image" class="equation" src="images/4935871849813661108-18.0px.png" width="274" height="18"/>(POLY INT) and then 
 > to
 > mainVariable$SMP as p, it is recognized as "case VPoly". So that must be where
 > the bug is, in coerce$(POLY INT).

Note that coerce$POLY only coerces to OutputForm?... No internal stuff done there. That's why I'm sure that it is an interpreter bug.

the original complaint --Tim Daly, Tue, 15 Feb 2005 20:39:05 -0600 reply
Problem: 
 (1) -> a:=1::DMP(['x],INT)

   (1)  1
               Type: DistributedMultivariatePolynomial([x],Integer)
 (2) -> a::POLY INT

   >> System error:
   Caught fatal error [memory may be damaged]

 protected-symbol-warn called with (NIL)
 (2) -> variables(a)

   (2)  []
                                           Type: List OrderedVariableList [x]
 (3) -> a::INT::POLY INT

   (3)  1
                                Type: Polynomial Integer

 (4) -> 1::DMP([x],INT)::POLY INT

   >> System error:
   Caught fatal error [memory may be damaged]

 protected-symbol-warn called with (NIL)

 (5) -> 1::DMP([x],INT)::DMP([y],INT)

   <a href="#eq5">(5)</a>  1
               Type: DistributedMultivariatePolynomial([y],Integer)

 and 

 1::POLY INT :: DMP([x],INT) 
 x::DMP([x],INT)::POLY INT
 1::DMP([x,y],INT)::POLY INT 
 1::EXPR INT:: POLY INT 
 1::UP(x,INT)::POLY INT

 and (surprise!) even

 1::DMP([x],INT)::POLY FRAC INT

 all worked!

This bug also exists in the NAG version, where the first (2) would give "Memory access violation detected". Two observations: (a) the coercion in (2), shows the interpreter does not follow the two steps in (3); and (b) the problem is specific to POLY INT. It may also have to do with the second (2), and my suspicion is that it has to do with a combination of the interpreter, POLY, DMP, INT, no variables, and may be POLYLIFT or MLIFT.

Tim: can you do a boot trace of (4) and compare that with any of the others that work?

fixed in FriCAS? --kratt6, Thu, 20 Dec 2007 01:45:47 -0800 reply
Status: open => fix proposed

... --gdr, Wed, 21 May 2008 02:23:07 -0700 reply
Status: fix proposed => fixed somewhere

no patch available

fixed? --Bill Page, Wed, 21 May 2008 07:49:14 -0700 reply
axiom
a:=1::DMP(['x],INT)
LatexWiki Image(1)
Type: DistributedMultivariatePolynomial?([x]?,Integer)
axiom
a::POLY INT
   >> System error:
   Caught fatal error [memory may be damaged]

axiom
1::POLY INT :: DMP([x],INT)
LatexWiki Image(2)
Type: DistributedMultivariatePolynomial?([x]?,Integer)
axiom
x::DMP([x],INT)::POLY INT
LatexWiki Image(3)
Type: Polynomial Integer
axiom
1::DMP([x,y],INT)::POLY INT
LatexWiki Image(4)
Type: Polynomial Integer
axiom
1::EXPR INT:: POLY INT
LatexWiki Image(5)
Type: Polynomial Integer
axiom
1::UP(x,INT)::POLY INT
LatexWiki Image(6)
Type: Polynomial Integer
axiom
1::DMP([x],INT)::POLY FRAC INT
LatexWiki Image(7)
Type: Polynomial Fraction Integer