Project

General

Profile

Bug #547

elim using RingTwinFloat triggers error "SERIOUS"

Added by John Abbott almost 10 years ago. Updated almost 8 years ago.

Status:
New
Priority:
Normal
Assignee:
-
Category:
Various
Target version:
CoCoALib-1.0
Start date:
05 May 2014
Due date:
% Done:

0%

Estimated time:
20.00 h
Spent time:
1.00 h

Description

The following (C5 input) provokes a SERIOUS error

K := NewRingTwinFloat(1024);
Ka ::= K[a[1]];
Coeffs := NewFractionField(Ka);
R ::= Coeffs[x,y];

Use R;
f := x^4 + 2*x^3 + 4*/*a[2]*/x^2 + a[1]*x^1 + /*a[0]*/x^0;
j := elim([x], Ideal(f,subst(f,x,x*y)));

simpler example: see #2

The fn throwing is RingTwinFloatImpl::myCompose

History

#1 Updated by John Abbott almost 10 years ago

I tried the same input with lower precisions and got InsuffPrec errors; but when I quit CoCoA-5 there were quite a few malloc errors!

#2 Updated by Anna Maria Bigatti almost 10 years ago

simpler example: both NewFractionField and NewRingTwinFloat seems necessary to trigger the error

K := NewFractionField(NewPolyRing(NewRingTwinFloat(1024), ["a"]));

Use R ::= K[x,y];
f := x + 1;
I := Ideal(f, subst(f,x,x*y)); I;
j := elim([x], I);

#3 Updated by Anna Maria Bigatti almost 10 years ago

  • Subject changed from SERIOUS: elim using RingTwinFloat to elim using RingTwinFloat triggers error "SERIOUS"

#4 Updated by John Abbott almost 8 years ago

I have confirmed that both examples still trigger ERR::SERIOUS with 5.1.5 on CoCoALib 0.99543.

Also available in: Atom PDF