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testBound -- Test whether b is bound for the semigroup L and compute a 1-parameter smoothing family if yes

Description

We check whether there exists a smoothing component for the restricted unfolding with variables of degree >b (or degree congruent 0 mod d for some d in congruences or variable with degree in the range). If the answer is yes, then we compute such smoothing family over QQ. This however might fail if the coefficient size is too small or the random choices in solvingFlatteningRelations are bad. In that case J will be null.

i1 : L={7,8,17,19,20}

o1 = {7, 8, 17, 19, 20}

o1 : List
i2 : (answer,J,comp)=testBound(L,12)
# of coordinate linear subspace of the base = 21
# of linear subsets which leading to a point =21

                    3             16      17                 2 13      19
o2 = (true, ideal (x  - x x  + x z   + x z  , x x  - x x  + x z   + x z   -
                1    0 3    1       0      1 5    0 6    0       1
         20   4               13    2 14      20   2      2        14      16
      x z  , x  - x x  + x x z   + x z   - x z  , x x  - x x  - x z   + x z
       0      0    1 6    0 1       0       1      1 3    0 5    5       3
        2 17        18    2 19   2    2      3 13      14    2 18         19
     + x z   + x x z   + x z  , x  - x x  + x z   - x z   + x z   + 2x x z
        1       0 1       0      3    0 6    0       6       1        0 1
        2 20      27     34          2        2 13      16      17      19
     - x z   + x z   - 2z  , x x  - x x  + x x z   - x z   - x z   + x z   -
        0       0             3 5    1 6    0 1       6       5       3
      2 20      29     36   3 2               13      2 14    3 16      17
     x z   + x z   - 2z  , x x  - x x  + x x z   + x x z   + x z   + x z   -
      1       0             0 1    3 6    0 3       0 1       0       6
        20    37   3      2    2   16    3 17      18      31     38   2
     x z   + z  , x x  - x  + x x z   + x z   + x z   - x z   + 2z  , x x x
      3            0 3    5    0 1       0       6       0             0 1 3
                   13      2 16    2   17    3 18      19      20    39   3
     - x x  + x x z   + x x z   + x x z   + x z   + x z   - x z   + z  , x x
       5 6    0 5       0 1       0 1       0       6       5            0 5
        2         13        14    3 19       20    2 26       33    40
     - x  + 2x x z   + x x z   + x z   - 2x z   - x z   + 3x z   - z  ), {0})
        6     0 6       0 5       0        6       0        0

o2 : Sequence
i3 : range=drop(flatten getRangeOfOneParameterFamily J,-5)

o3 = {13, 14, 16, 17, 18, 19, 20, 26, 27, 29, 31, 33, 34}

o3 : List
i4 : (answer1,J1,comp)=testRange(L,range,CoeffSize=>2)
# of coordinate linear subspace of the base = 6
# of linear subsets which leading to a point =4

                 3               16       17                  2 13   4
o4 = (true, ideal (2x  - 2x x  + 6x z   + 3x z  , x x  - x x  + 3x z  , x  -
                 1     0 3     1        0      1 5    0 6     0      0
              13     2 14    2       2         13        14        16
 x x  + 4x x z   + 2x z  , 8x x  - 8x x  - 8x z   - 16x z   + 24x z   +
  1 6     0 1        0       1 3     0 5     6         5         3
        18      2 19        26    2     2        3 13        14        17
 27x x z   + 18x z   + 24x z  , 8x  - 8x x  + 16x z   - 16x z   - 12x z
    0 1         0         0       3     0 6      0         6         3
      2 18          19       26        27            2         2 13
 + 27x z   + 18x x z   - 8x z   + 32x z  , 2x x  - 2x x  + 6x x z   -
      1         0 1        1         0       3 5     1 6     0 1
     16       17        29    3 2                 13       2 14     3 16
 6x z   - 3x z   + 18x z  , 2x x  - 2x x  + 8x x z   + 4x x z   + 6x z
   6        5         0       0 1     3 6     0 3        0 1        0
       17    3       2      2   16        18        19         31
 + 3x z  , 8x x  - 8x  + 24x x z   + 27x z   + 18x z   - 108x z  ,
     6       0 3     5      0 1         6         5          0
   2                      13        2 16      3 18        19   3      2
 8x x x  - 8x x  + 24x x z   + 24x x z   + 27x z   + 18x z  , x x  - x  +
   0 1 3     5 6      0 5         0 1         0         6      0 5    6
       13         14      2 26
 7x x z   + 2x x z   - 12x z  ), {0})
   0 6        0 5         0

o4 : Sequence
i5 : J_*/size

o5 = {4, 5, 5, 7, 9, 9, 8, 7, 9, 9}

o5 : List
i6 : J1_*/size

o6 = {4, 3, 4, 8, 9, 6, 6, 6, 6, 5}

o6 : List
i7 : congruences={6}

o7 = {6}

o7 : List
i8 : (answer,J,comp)=testCongruences(L,congruences,Verbose=>2)

o8 = (false, , {})

o8 : Sequence

See also

Ways to use testBound:

  • testBound(List,ZZ)

For the programmer

The object testBound is a method function with options.


The source of this document is in WeierstrassSemigroups.m2:2461:0.