Macaulay2 / Macaulay2/M2

makeSimplicial in NormalToricVarieties occasionally makes the variety incomplete

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NormalToricVarieties
Dominant language
Macaulay2
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297
Avg merge
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Merged PRs (30d)
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Description

Here is an example:
```m2
needsPackage "NormalToricVarieties"

-- Bruns and Gubeladze Example 5.1
P = convexHull matrix transpose {
{1,1,1,0,0,0}, {0,1,1,0,0,1},
{1,1,0,1,0,0}, {0,1,0,1,1,0},
{1,0,1,0,1,0}, {0,1,0,0,1,1},
{1,0,0,1,0,1}, {0,0,1,1,1,0},
{1,0,0,0,1,1}, {0,0,1,1,0,1}}
N = ZZ^5
P = affineImage(id_N | transpose matrix {{-1,-1,-1,-1,-1}}, P)

tally apply(100, i -> (
X := normalToricVariety P;
assert isComplete X;
isComplete makeSimplicial X))
```
And the result:
```m2
o5 = Tally{false => 15}
true => 85
```
(I didn't test projectivity because it is slower to check, but of course these should always be projective as well.)

cc: @ggsmith

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Research direction

No source file or test is identified in the issue. Start by running the provided Macaulay2 reproduction and inspect the implementation of makeSimplicial; done means the resulting variety remains complete, with projectivity also preserved if checked.

Written by the indexing model from the issue text.

Assessment

Domain
tooling
Issue type
Bug
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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