run "date"; load "InvariantPolynomialsforMukaiModels.m2"; matrixFromHyperplaneEquations = (L) -> ( R:=ring(L_0); eqnMatrix:=matrix apply(L, f -> apply(numgens R, i -> coefficient(R_i,f))); transpose gens ker eqnMatrix ); -- The ordering and numbering here match Theorem 4.1 in the preprint -- Genus 7 S=QQ[x_0,x_12,x_13,x_14,x_15,x_23,x_24,x_25,x_34,x_35,x_45,x_1234,x_1235,x_1245,x_1345,x_2345]; -- Example 7a: the genus 7 tangent developable LTD7 = {x_13, x_23+(5/3)*x_15, x_24, x_34-5*x_25, x_45-(4/3)*x_35, x_1245-(9/8)*x_1235, x_1345+(1/2)*x_12, x_2345+(2/15)*x_14}; F72(matrixFromHyperplaneEquations LTD7) -- Example 7b: the genus 7 cuspidal cubic with 7-gonal symmetry LCusp7 = {x_13, x_23+(5/3)*x_15, x_24, x_34-5*x_25, x_45-(4/3)*x_35, x_1245-(9/8)*x_1235, x_1345+(1/2)*x_12, x_2345+(2/15)*x_14,x_1234-1/30*x_0}; F71(matrixFromHyperplaneEquations LCusp7) -- Example 7c: the genus 7 balanced K3 carpet LK3Carpet7 = {x_0, x_12-x_1345, x_13-x_2345, x_24-2*x_15, x_34-1/2*x_25, x_45, x_1234, x_1235}; F72(matrixFromHyperplaneEquations LK3Carpet7) -- Example 7d: the genus 7 balanced ribbon LBalRib7 = {x_0, x_12-x_1345, x_13-x_2345, x_24-2*x_15, x_34-1/2*x_25, x_45, x_1234, x_1235, x_23-x_14}; F71(matrixFromHyperplaneEquations LBalRib7) -- Example 7e: a genus 7 graph curve LGraphCurve7={x_2345, x_1245, x_1234, x_35, x_23-x_25, x_15+x_25-x_35-x_45, x_14, x_12-x_13, x_0+x_25-x_35-x_45}; F71(matrixFromHyperplaneEquations LGraphCurve7) -- Genus 8 K = toField(QQ[sqrt2,Degrees=>{0}]/ideal(sqrt2^2-2)); -- The order of the variables shown here is grevlex for subsets -- Do this to match M2's exteriorPower function R = K[x_12,x_13,x_23,x_14,x_24,x_34,x_15,x_25,x_35,x_45,x_16,x_26,x_36,x_46,x_56]; -- Example 8a: the genus 8 tangent developable LTD8 = {x_23-(5/3)*x_14, x_24-5*x_15, x_25-15*x_16, x_34-20*x_16, x_35-5*x_26, x_45-(5/3)*x_36}; F82(matrixFromHyperplaneEquations LTD8) -- Example 8b: the genus 8 cuspidal cubic with 8-gonal symmetry LCusp8 = {x_23-(5/3)*x_14, x_24-5*x_15, x_25-15*x_16, x_34-20*x_16, x_35-5*x_26, x_45-(5/3)*x_36, x_12-x_56}; F81(matrixFromHyperplaneEquations LCusp8) -- Example 8c: a genus 8 reducible surface with four components, each generically nonreduced LNonRedSurf8 = {x_12-x_34, x_12-x_13, x_14-x_45, x_16-x_23, x_24-x_35, x_26-x_36}; F82(matrixFromHyperplaneEquations LNonRedSurf8) -- Example 8d: a genus 8 reducible curve with five components, each generically nonreduced: LNonRedCurve8={x_12-x_34, x_12-x_13, x_14-x_45, x_16-x_23, x_24-x_35, x_26-x_36, x_15-x_46}; F81(matrixFromHyperplaneEquations LNonRedCurve8) -- Example 8e: a genus 8 graph curve LGraphCurve8 = {x_12-32*x_46, x_13+(64*sqrt2 - 96)*x_56, x_14+(1/32)*x_23, x_15-x_24, x_16+(1/32*(2*sqrt2 + 3))*x_35, x_25-x_34, x_26-x_45}; F81(matrixFromHyperplaneEquations LGraphCurve8) -- Genus 9 -- Example 9a: the genus 9 tangent developable K = toField(QQ[sqrt3,Degrees=>{0}]/(sqrt3^2-3)); S = K[z_0..z_13]; LTD9 = {z_3-(135/2)*z_4,z_9-(1/432)*z_10,z_5-45*z_12,z_6 + 36*z_11}; F92(matrixFromHyperplaneEquations LTD9) -- Example 9b: the genus 9 cuspidal cubic with 9-gonal symmetry LCusp9 = {z_3-(135/2)*z_4,z_9-(1/432)*z_10,z_5-45*z_12,z_6 + 36*z_11,z_0+1/5*z_13}; F91(matrixFromHyperplaneEquations LCusp9) -- Example 9c: the genus 9 balanced K3 carpet LK3Carpet9 = {z_0,z_13,z_3+1/2*z_4,z_9+1/2*z_10}; F92(matrixFromHyperplaneEquations LK3Carpet9) -- Example 9d: the genus 9 balanced ribbon: LBalRib9 = {z_0,z_13,z_3+1/2*z_4,z_9+1/2*z_10,z_1-4*z_7}; F91(matrixFromHyperplaneEquations LBalRib9) -- Example 9e: a genus 9 graph curve LGraphCurve9= {z_0-(12*sqrt3 - 18)*z_13, z_4-((4/9)*sqrt3+2/3)*z_3, z_6-(12*sqrt3-21)*z_1, z_10-(-6*sqrt3 + 9)*z_9, z_12+1/3*z_7 }; F91(matrixFromHyperplaneEquations LGraphCurve9) -- Genus 10 S = QQ[H_1,H_2,X_1,X_2,X_3,X_4,X_5,X_6,Y_1,Y_2,Y_3,Y_4,Y_5,Y_6]; -- Example 10a: the genus 10 tangent developable LTD10={H_1-4/9*H_2, X_3-4/27*Y_6, Y_3-5/4*X_6}; F102(matrixFromHyperplaneEquations LTD10) -- Example 10b: the genus 10 cuspidal cubic with 10-gonal symmetry LCusp10={H_1-4/9*H_2, X_3-4/27*Y_6, Y_3-5/4*X_6,X_5+8/75*Y_5}; F101(matrixFromHyperplaneEquations LCusp10) -- Example 10c: a genus 10 reducible surface with two components, each generically nonreduced LNonRedSurf10 = {X_1-Y_1,Y_2-Y_3,X_4-X_5}; F102(matrixFromHyperplaneEquations LNonRedSurf10) -- Example 10d: a genus 10 reducible curve with three components, each generically nonreduced LNonRedCurve10 = {X_1-Y_1,Y_2-Y_3,X_4-X_5,H_1-Y_5}; F101(matrixFromHyperplaneEquations LNonRedCurve10) run "date"; quit