i1 : S = surface {4,5,1};
o1 : ProjectiveVariety, surface in PP^6
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i2 : V = random(3,S);
o2 : ProjectiveVariety, hypersurface in PP^6
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i3 : X = V * random(2,S);
o3 : ProjectiveVariety, 4-dimensional subvariety of PP^6
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i4 : F = specialFourfold(S,X,V);
o4 : ProjectiveVariety, complete intersection of type (2,3) in PP^6 containing a surface of degree 7 and sectional genus 2
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i5 : ambientFivefold F
o5 = V
o5 : ProjectiveVariety, hypersurface in PP^6
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i6 : X = specialFourfold("21",ZZ/33331);
o6 : ProjectiveVariety, GM fourfold containing a surface of degree 12 and sectional genus 5
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i7 : describe X
o7 = Special Gushel-Mukai fourfold of discriminant 26(')
containing a surface in PP^8 of degree 12 and sectional genus 5
cut out by 16 hypersurfaces of degree 2
and with class in G(1,4) given by 7*s_(3,1)+5*s_(2,2)
Type: ordinary
(case 21 of Table 1 in arXiv:2002.07026)
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i8 : Y = ambientFivefold X;
o8 : ProjectiveVariety, 5-dimensional subvariety of PP^8
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i9 : isSubset(X,Y)
o9 = true
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i10 : Y!
dim:.................. 5
codim:................ 3
degree:............... 5
sectional genus:...... 1
generators:........... 2^5
linear normality:..... true
connected components:. 1
purity:............... true
dim sing. l.:......... -1
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