-- -*- M2-comint -*- {* hash: -2037591551 *} i1 : KK = ZZ/32003 o1 = KK o1 : QuotientRing i2 : R = KK[x,y,z,w] o2 = R o2 : PolynomialRing i3 : I = ideal(x^2*y,x*y^2+x^3) 2 3 2 o3 = ideal (x y, x + x*y ) o3 : Ideal of R i4 : J = gens gb I o4 = | x2y x3+xy2 xy3 | 1 3 o4 : Matrix R <--- R i5 : R = KK[x,y,z,w,MonomialOrder=>Lex] o5 = R o5 : PolynomialRing i6 : I = substitute(I,R) 2 3 2 o6 = ideal (x y, x + x*y ) o6 : Ideal of R i7 : gens gb I o7 = | xy3 x2y x3+xy2 | 1 3 o7 : Matrix R <--- R i8 : R = KK[x,y,z] o8 = R o8 : PolynomialRing i9 : F = random(R^1, R^{-2,-3}) o9 = | 4784x2+7336xy+5204y2-13630xz-5803yz+178z2 ------------------------------------------------------------------------ 4812x3-5078x2y+1744xy2-8124y3+711x2z+12462xyz-1117y2z+7264xz2-3703yz2+ ------------------------------------------------------------------------ 13609z3 | 1 2 o9 : Matrix R <--- R i10 : GB = gens gb F o10 = | x2+15896xy-12281y2-12887xz+6481yz+281z2 ----------------------------------------------------------------------- xy2+2071y3-14824xyz-3889y2z-11159xz2+11464yz2-12986z3 ----------------------------------------------------------------------- y4+1199y3z-14666xyz2+15864y2z2-12070xz3-8899yz3-13623z4 | 1 3 o10 : Matrix R <--- R i11 : LT = leadTerm GB o11 = | x2 xy2 y4 | 1 3 o11 : Matrix R <--- R i12 : betti LT 0 1 o12 = total: 1 3 0: 1 . 1: . 1 2: . 1 3: . 1 o12 : BettiTally i13 : R = KK[x,y,z, MonomialOrder => Lex] o13 = R o13 : PolynomialRing i14 : F = random(R^1, R^{-2,-3}) o14 = | -9607x2-2779xy-6990xz-13967y2-8493yz+4601z2 ----------------------------------------------------------------------- -3927x3+8362x2y+2217x2z+1456xy2+5336xyz-2384xz2-15285y3-15520y2z+ ----------------------------------------------------------------------- 7367yz2+14266z3 | 1 2 o14 : Matrix R <--- R i15 : GB = gens gb F o15 = | y6-10565y5z-2181y4z2+15036y3z3-8915y2z4-125yz5-13748z6 ----------------------------------------------------------------------- xz4-5444y5+10927y4z-635y3z2+5108y2z3-922yz4-13864z5 ----------------------------------------------------------------------- xyz2-2574xz3+3653y4-245y3z-12393y2z2+14708yz3+13496z4 ----------------------------------------------------------------------- xy2+15472xyz-1817xz2-9110y3-2993y2z-13510yz2+9710z3 ----------------------------------------------------------------------- x2+11473xy-13544xz-4006y2+13459yz+13411z2 | 1 5 o15 : Matrix R <--- R i16 : LT = leadTerm GB o16 = | y6 xz4 xyz2 xy2 x2 | 1 5 o16 : Matrix R <--- R i17 : betti LT 0 1 o17 = total: 1 5 0: 1 . 1: . 1 2: . 1 3: . 1 4: . 1 5: . 1 o17 : BettiTally i18 : R = KK[a..i] o18 = R o18 : PolynomialRing i19 : M = genericMatrix(R,a,3,3) o19 = | a d g | | b e h | | c f i | 3 3 o19 : Matrix R <--- R i20 : N = M^3 o20 = | a3+2abd+bde+2acg+bfg+cdh+cgi | a2b+b2d+abe+be2+bcg+ach+ceh+bfh+chi | a2c+bcd+abf+bef+c2g+cfh+aci+bfi+ci2 ----------------------------------------------------------------------- a2d+bd2+ade+de2+cdg+afg+efg+dfh+fgi a2g+bdg+cg2+adh+deh+fgh+agi+dhi+gi2 abd+2bde+e3+bfg+cdh+2efh+fhi abg+beg+bdh+e2h+cgh+fh2+bgi+ehi+hi2 acd+cde+bdf+e2f+cfg+f2h+cdi+efi+fi2 acg+bfg+cdh+efh+2cgi+2fhi+i3 ----------------------------------------------------------------------- | | | 3 3 o20 : Matrix R <--- R i21 : I = flatten N o21 = | a3+2abd+bde+2acg+bfg+cdh+cgi a2b+b2d+abe+be2+bcg+ach+ceh+bfh+chi ----------------------------------------------------------------------- a2c+bcd+abf+bef+c2g+cfh+aci+bfi+ci2 a2d+bd2+ade+de2+cdg+afg+efg+dfh+fgi ----------------------------------------------------------------------- abd+2bde+e3+bfg+cdh+2efh+fhi acd+cde+bdf+e2f+cfg+f2h+cdi+efi+fi2 ----------------------------------------------------------------------- a2g+bdg+cg2+adh+deh+fgh+agi+dhi+gi2 abg+beg+bdh+e2h+cgh+fh2+bgi+ehi+hi2 ----------------------------------------------------------------------- acg+bfg+cdh+efh+2cgi+2fhi+i3 | 1 9 o21 : Matrix R <--- R i22 : Tr = trace M o22 = a + e + i o22 : R i23 : Tr //I -- the quotient, which is 0 o23 = 0 9 1 o23 : Matrix R <--- R i24 : Tr % I -- the remainder, which is Tr again o24 = a + e + i o24 : R i25 : Tr^2 % I 2 2 2 o25 = a + 2a*e + e + 2a*i + 2e*i + i o25 : R i26 : Tr^3 % I 2 2 3 2 o26 = 3a e + 3b*d*e + 3a*e + 3e + 3b*f*g + 3c*d*h + 6e*f*h + 3a i + 6a*e*i ----------------------------------------------------------------------- 2 2 2 3 + 3e i + 3c*g*i + 6f*h*i + 3a*i + 3e*i + 3i o26 : R i27 : Tr^4 % I 2 2 2 3 4 o27 = 6a e + 6b*d*e + 6a*e + 6e + 6b*e*f*g + 6c*d*e*h - 6b*d*f*h + ----------------------------------------------------------------------- 2 2 2 2 2 6a*e*f*h + 12e f*h - 6c*f*g*h - 6f h + 12a e*i + 12b*d*e*i + 12a*e i + ----------------------------------------------------------------------- 3 2 2 12e i + 12c*e*g*i + 6b*f*g*i + 6c*d*h*i + 6a*f*h*i + 36e*f*h*i + 6a i ----------------------------------------------------------------------- 2 2 2 2 2 3 3 4 + 12a*e*i + 6e i + 6c*g*i + 12f*h*i + 6a*i + 12e*i + 6i o27 : R i28 : Tr^5 % I 2 2 2 3 4 2 2 o28 = 30a e i + 30b*d*e i + 30a*e i + 30e i + 30c*e g*i + 30a f*h*i + ----------------------------------------------------------------------- 2 2 2 30b*d*f*h*i + 60a*e*f*h*i + 90e f*h*i + 30c*f*g*h*i + 30f h i + ----------------------------------------------------------------------- 2 2 2 2 2 3 2 2 2 30a e*i + 30b*d*e*i + 30a*e i + 30e i + 30c*e*g*i + 60a*f*h*i + ----------------------------------------------------------------------- 2 2 3 3 3 2 3 3 120e*f*h*i + 30a i + 30b*d*i + 30a*e*i + 30e i + 30c*g*i + ----------------------------------------------------------------------- 3 4 4 5 90f*h*i + 30a*i + 30e*i + 30i o28 : R i29 : Tr^6 % I 2 2 2 2 2 3 2 4 2 2 2 2 2 o29 = 90a e i + 90b*d*e i + 90a*e i + 90e i + 90c*e g*i + 90a f*h*i + ----------------------------------------------------------------------- 2 2 2 2 2 2 2 2 90b*d*f*h*i + 180a*e*f*h*i + 270e f*h*i + 90c*f*g*h*i + 90f h i + ----------------------------------------------------------------------- 2 3 3 2 3 3 3 3 3 90a e*i + 90b*d*e*i + 90a*e i + 90e i + 90c*e*g*i + 180a*f*h*i + ----------------------------------------------------------------------- 3 2 4 4 4 2 4 4 360e*f*h*i + 90a i + 90b*d*i + 90a*e*i + 90e i + 90c*g*i + ----------------------------------------------------------------------- 4 5 5 6 270f*h*i + 90a*i + 90e*i + 90i o29 : R i30 : Tr^7 % I o30 = 0 o30 : R i31 : Tr^6 // I o31 = {3} | a3+6a2e+3bde+15ae2+22e3+6efh+6a2i+30aei+60e2i+6fhi+15ai2+60ei2+22 {3} | 0 {3} | 0 {3} | -27abe-45be2+9ceh+30bfh-72abi-144bei+75chi {3} | -2a3+15a2e+21bde+6ae2+e3+33bfg+9cdh-36afh+51efh+60a2i+72bdi+30aei {3} | 18abg+45beg+3a2h+9bdh-21aeh+3e2h+9cgh+36fh2+114bgi-135ahi-39ehi+3 {3} | 18ace+6abf-36bef-18cfh+66aci+36cei-57bfi+132ci2 {3} | -3a2f-39bdf+75aef-12e2f+9cfg-36f2h-66cdi+135afi+51efi+69fi2 {3} | -2a3-18abd-30a2e-60bde-30ae2-44e3-18ceg-33bfg-9cdh+18afh-93efh-75 ----------------------------------------------------------------------- i3 | | | | +6e2i+66cgi+147fhi-30ai2-75ei2-26i3 | 6hi2 | | | a2i-90bdi-60aei-75e2i-66cgi-171fhi-84ai2-84ei2-89i3 | 9 1 o31 : Matrix R <--- R i32 : Tr^6 == I * (Tr^6 // I) + (Tr^6 % I) o32 = true i33 : R = KK[t,y,z,MonomialOrder=>Lex] o33 = R o33 : PolynomialRing i34 : I = ideal(y-(t^2+t+1), z-(t^3+1)) 2 3 o34 = ideal (- t - t + y - 1, - t + z - 1) o34 : Ideal of R i35 : GB = gens gb I o35 = | y3-3y2-3yz+6y-z2+4z-4 tz-2t-y2+3y+2z-4 ty-y-z+2 t2+t-y+1 | 1 4 o35 : Matrix R <--- R i36 : F = GB_(0,0) 3 2 2 o36 = y - 3y - 3y*z + 6y - z + 4z - 4 o36 : R i37 : substitute(F, {y =>t^2+t+1, z=>t^3+1}) o37 = 0 o37 : R i38 : R = KK[y,z,t] o38 = R o38 : PolynomialRing i39 : I = substitute(I,R) 2 3 o39 = ideal (- t + y - t - 1, - t + z - 1) o39 : Ideal of R i40 : eliminate(I,t) 3 2 2 o40 = ideal(y - 3y - 3y*z - z + 6y + 4z - 4) o40 : Ideal of R i41 : A = KK[t] o41 = A o41 : PolynomialRing i42 : B = KK[y,z] o42 = B o42 : PolynomialRing i43 : G = map(A,B,{t^2+t+1, t^3+1}) 2 3 o43 = map(A,B,{t + t + 1, t + 1}) o43 : RingMap A <--- B i44 : kernel G 3 2 2 o44 = ideal(y - 3y - 3y*z - z + 6y + 4z - 4) o44 : Ideal of B i45 : R = KK[t,x,y,z] o45 = R o45 : PolynomialRing i46 : I = ideal(x^3,y^3,z^3) 3 3 3 o46 = ideal (x , y , z ) o46 : Ideal of R i47 : F = x+y+z o47 = x + y + z o47 : R i48 : L = t*I + (1-t)*ideal(F) 3 3 3 o48 = ideal (t*x , t*y , t*z , - t*x - t*y - t*z + x + y + z) o48 : Ideal of R i49 : L1 = eliminate(L,t) 3 3 4 3 4 3 3 4 3 3 3 o49 = ideal (x*z + y*z + z , x*y + y + y z, x y + y - x z + 2y z - 2y*z ----------------------------------------------------------------------- 4 4 4 3 3 3 4 3 2 3 2 2 3 4 - z , x - y + 2x z - 2y z + 2y*z + z , x z + y z + 3y z + 3y*z + ----------------------------------------------------------------------- 5 z ) o49 : Ideal of R i50 : gens gb L1 o50 = | xz3+yz3+z4 xy3+y4+y3z x3y+y4-x3z+2y3z-2yz3-z4 x4-y4+2x3z-2y3z+2yz3+z4 ----------------------------------------------------------------------- x3z2+y3z2+3y2z3+3yz4+z5 | 1 5 o50 : Matrix R <--- R i51 : (gens L1) % F o51 = 0 1 5 o51 : Matrix R <--- R i52 : J = ideal ((gens L1)//F) 3 3 2 2 3 2 2 2 2 3 3 2 o52 = ideal (z , y , x y - x*y + y - x z + y z + x*z - y*z - z , x - x y ----------------------------------------------------------------------- 2 3 2 2 2 2 3 2 2 2 2 2 3 + x*y - y + x z - y z - x*z + y*z + z , x z - x*y*z + y z - x*z ----------------------------------------------------------------------- 3 4 + 2y*z + z ) o52 : Ideal of R i53 : mingens J o53 = | z3 y3 x2y-xy2-x2z+y2z+xz2-yz2 x3 x2z2-xyz2+y2z2 | 1 5 o53 : Matrix R <--- R i54 : betti oo 0 1 o54 = total: 1 5 0: 1 . 1: . . 2: . 4 3: . 1 o54 : BettiTally i55 : R = KK[x,y,z] o55 = R o55 : PolynomialRing i56 : I = ideal(x^3,y^3,z^3) 3 3 3 o56 = ideal (x , y , z ) o56 : Ideal of R i57 : F = x+y+z o57 = x + y + z o57 : R i58 : J = I : F 3 3 2 2 2 2 2 2 3 2 2 2 o58 = ideal (z , y , x y - x*y - x z + y z + x*z - y*z , x , x z - x*y*z ----------------------------------------------------------------------- 2 2 + y z ) o58 : Ideal of R i59 : betti J 0 1 o59 = total: 1 5 0: 1 . 1: . . 2: . 4 3: . 1 o59 : BettiTally i60 : transpose gens J o60 = {-3} | z3 | {-3} | y3 | {-3} | x2y-xy2-x2z+y2z+xz2-yz2 | {-3} | x3 | {-4} | x2z2-xyz2+y2z2 | 5 1 o60 : Matrix R <--- R i61 : transpose gens gb J o61 = {-3} | z3 | {-3} | y3 | {-3} | x2y-xy2-x2z+y2z+xz2-yz2 | {-3} | x3 | {-4} | x2z2-xyz2+y2z2 | 5 1 o61 : Matrix R <--- R i62 : R = KK[t,a..f] o62 = R o62 : PolynomialRing i63 : I = ideal(a*b*c-d*e*f, a^2*b-c^2*d, a*f^2-d*b*c) 2 2 2 o63 = ideal (a*b*c - d*e*f, a b - c d, - b*c*d + a*f ) o63 : Ideal of R i64 : F = a*b*c*d*e*f o64 = a*b*c*d*e*f o64 : R i65 : J = eliminate(I + ideal(t*F-1), t) 2 2 2 2 3 o65 = ideal (d e - a f, b*d*e - c f, b*c*d - a*f , c - a*e*f, a*b*c - d*e*f, ----------------------------------------------------------------------- 2 2 2 2 3 4 2 2 3 a*b - c*f , a b - c d, b d - f , b c - e*f ) o65 : Ideal of R i66 : transpose gens J o66 = {-3} | d2e-a2f | {-3} | bde-c2f | {-3} | bcd-af2 | {-3} | c3-aef | {-3} | abc-def | {-3} | ab2-cf2 | {-3} | a2b-c2d | {-4} | b3d-f4 | {-4} | b2c2-ef3 | 9 1 o66 : Matrix R <--- R i67 : R = KK[a..f] o67 = R o67 : PolynomialRing i68 : I = substitute(I,R) 2 2 2 o68 = ideal (a*b*c - d*e*f, a b - c d, - b*c*d + a*f ) o68 : Ideal of R i69 : F = product gens R o69 = a*b*c*d*e*f o69 : R i70 : J' = saturate(I,F) 2 2 2 2 3 o70 = ideal (d e - a f, b*d*e - c f, b*c*d - a*f , c - a*e*f, a*b*c - d*e*f, ----------------------------------------------------------------------- 2 2 2 2 3 4 2 2 3 a*b - c*f , a b - c d, b d - f , b c - e*f ) o70 : Ideal of R i71 : transpose gens J' o71 = {-3} | d2e-a2f | {-3} | bde-c2f | {-3} | bcd-af2 | {-3} | c3-aef | {-3} | abc-def | {-3} | ab2-cf2 | {-3} | a2b-c2d | {-4} | b3d-f4 | {-4} | b2c2-ef3 | 9 1 o71 : Matrix R <--- R i72 :