generic derivation : delta:= mat((xi(1,1),0,0,0,0,0),(xi(2,1),xi(2,2),xi(2,3),0,0,0),(xi(3,1),xi(3,2),xi(3,3) ,0,0,0),(xi(4,1),xi(4,2),xi(4,3),xi(2,2) + xi(1,1),xi(2,3),xi(4,6)),(xi(5,1),xi( 5,2),xi(5,3),xi(3,2),xi(3,3) + xi(1,1),xi(5,6)),(xi(6,1),xi(6,2),xi(6,3),0,0,xi( 6,6)))$ [0 0 0 0 0 0] [ ] [0 0 0 0 0 0] [ ] [0 0 0 0 0 0] adx1 := [ ] [0 1 0 0 0 0] [ ] [0 0 1 0 0 0] [ ] [0 0 0 0 0 0] [0 0 0 0 0 0] [ ] [0 0 0 0 0 0] [ ] [0 0 0 0 0 0] adx2 := [ ] [-1 0 0 0 0 0] [ ] [0 0 0 0 0 0] [ ] [0 0 0 0 0 0] [0 0 0 0 0 0] [ ] [0 0 0 0 0 0] [ ] [0 0 0 0 0 0] adx3 := [ ] [0 0 0 0 0 0] [ ] [-1 0 0 0 0 0] [ ] [0 0 0 0 0 0] The generic nilpotent derivation : the eigenvalues are 0 xi(1,1):=0 xi(6,6):=0 And the matrix A:=(xi(2,2),xi(2,3)),(xi(3,2),xi(3,3)) is nilpotent We hence get 2 cases according to whether A neq 0 or A=0. We consider here the case 1 where A = 0. In that case, one may suppose A:=((0,0),(0,0)). xi(2,2):=0 xi(2,3):=0 xi(3,2):=0 xi(3,3):=0 by subtracting adjoints one then may suppose: xi(4,1):=0,xi(4,2):=0,xi(5,1):=0 delta:= [ 0 0 0 0 0 0 ] [ ] [xi(2,1) 0 0 0 0 0 ] [ ] [xi(3,1) 0 0 0 0 0 ] [ ] [ 0 0 xi(4,3) 0 0 xi(4,6)] [ ] [ 0 xi(5,2) xi(5,3) 0 0 xi(5,6)] [ ] [xi(6,1) xi(6,2) xi(6,3) 0 0 0 ] We denote this delta by the shortform shortformdelta:={xi(2,1), xi(3,1), xi(6,1), ss, xi(5,2), xi(6,2), ss, xi(4,3), xi(5,3), xi(6,3), ss, xi(4,6), xi(5,6)} paramindexeslist:={{2,1}, {3,1}, {6,1}, {5,2}, {6,2}, {4,3}, {5,3}, {6,3}, {4,6}, {5,6}} a:=0$ b:=0$ delta:= mat((0,0,0,0,0,0),(0,0,0,0,0,0),(0,0,0,0,0,0),(0,0,0,0,0,1),(0,0,0,0,0,0),(0,0,0 ,0,0,0))$ shortformdelta:={0,0,0,ss,0,0,ss,0,0,0,ss,1,0}$ on resout l'equation {{0,1},4} qui est maintenant AA:=d(6,1) - d(2,0)$ Unknowns: {d(6,1),d(2,0)} Unknowns: {d(6,1),d(2,0)} bonne inconnue W:=d(6,1)$ sa valeur doit etre WW:=d(2,0)$ on resout l'equation {{0,1},5} qui est maintenant AA:= - d(3,0)$ Unknown: d(3,0) Unknown: d(3,0) bonne inconnue W:=d(3,0)$ sa valeur doit etre WW:=0$ on resout l'equation {{0,2},4} qui est maintenant AA:=d(6,2) + d(1,0)$ Unknowns: {d(6,2),d(1,0)} Unknowns: {d(6,2),d(1,0)} bonne inconnue W:=d(6,2)$ sa valeur doit etre WW:= - d(1,0)$ on resout l'equation {{0,3},4} qui est maintenant AA:=d(6,3)$ Unknown: d(6,3) Unknown: d(6,3) bonne inconnue W:=d(6,3)$ sa valeur doit etre WW:=0$ on resout l'equation {{0,3},5} qui est maintenant AA:=d(1,0)$ Unknown: d(1,0) Unknown: d(1,0) bonne inconnue W:=d(1,0)$ sa valeur doit etre WW:=0$ on resout l'equation {{0,4},4} qui est maintenant AA:=d(6,4)$ Unknown: d(6,4) Unknown: d(6,4) bonne inconnue W:=d(6,4)$ sa valeur doit etre WW:=0$ on resout l'equation {{0,5},4} qui est maintenant AA:=d(6,5)$ Unknown: d(6,5) Unknown: d(6,5) bonne inconnue W:=d(6,5)$ sa valeur doit etre WW:=0$ on resout l'equation {{0,6},0} qui est maintenant AA:= - d(0,4)$ Unknown: d(0,4) Unknown: d(0,4) bonne inconnue W:=d(0,4)$ sa valeur doit etre WW:=0$ on resout l'equation {{0,6},1} qui est maintenant AA:= - d(1,4)$ Unknown: d(1,4) Unknown: d(1,4) bonne inconnue W:=d(1,4)$ sa valeur doit etre WW:=0$ on resout l'equation {{0,6},2} qui est maintenant AA:= - d(2,4)$ Unknown: d(2,4) Unknown: d(2,4) bonne inconnue W:=d(2,4)$ sa valeur doit etre WW:=0$ on resout l'equation {{0,6},3} qui est maintenant AA:= - d(3,4)$ Unknown: d(3,4) Unknown: d(3,4) bonne inconnue W:=d(3,4)$ sa valeur doit etre WW:=0$ on resout l'equation {{0,6},4} qui est maintenant AA:=d(6,6) - d(4,4) + d(0,0)$ Unknowns: {d(6,6),d(4,4),d(0,0)} Unknowns: {d(6,6),d(4,4),d(0,0)} bonne inconnue W:=d(6,6)$ sa valeur doit etre WW:=d(4,4) - d(0,0)$ on resout l'equation {{0,6},5} qui est maintenant AA:= - d(5,4)$ Unknown: d(5,4) Unknown: d(5,4) bonne inconnue W:=d(5,4)$ sa valeur doit etre WW:=0$ on resout l'equation {{1,2},4} qui est maintenant AA:= - d(4,4) + d(2,2) + d(1, 1)$ Unknowns: {d(4,4),d(2,2),d(1,1)} Unknowns: {d(4,4),d(2,2),d(1,1)} bonne inconnue W:=d(4,4)$ sa valeur doit etre WW:=d(2,2) + d(1,1)$ on resout l'equation {{1,2},5} qui est maintenant AA:=d(3,2)$ Unknown: d(3,2) Unknown: d(3,2) bonne inconnue W:=d(3,2)$ sa valeur doit etre WW:=0$ on resout l'equation {{1,3},0} qui est maintenant AA:= - d(0,5)$ Unknown: d(0,5) Unknown: d(0,5) bonne inconnue W:=d(0,5)$ sa valeur doit etre WW:=0$ on resout l'equation {{1,3},1} qui est maintenant AA:= - d(1,5)$ Unknown: d(1,5) Unknown: d(1,5) bonne inconnue W:=d(1,5)$ sa valeur doit etre WW:=0$ on resout l'equation {{1,3},2} qui est maintenant AA:= - d(2,5)$ Unknown: d(2,5) Unknown: d(2,5) bonne inconnue W:=d(2,5)$ sa valeur doit etre WW:=0$ on resout l'equation {{1,3},3} qui est maintenant AA:= - d(3,5)$ Unknown: d(3,5) Unknown: d(3,5) bonne inconnue W:=d(3,5)$ sa valeur doit etre WW:=0$ on resout l'equation {{1,3},4} qui est maintenant AA:= - d(4,5) + d(2,3)$ Unknowns: {d(4,5),d(2,3)} Unknowns: {d(4,5),d(2,3)} bonne inconnue W:=d(4,5)$ sa valeur doit etre WW:=d(2,3)$ on resout l'equation {{1,3},5} qui est maintenant AA:= - d(5,5) + d(3,3) + d(1, 1)$ Unknowns: {d(5,5),d(3,3),d(1,1)} Unknowns: {d(5,5),d(3,3),d(1,1)} bonne inconnue W:=d(5,5)$ sa valeur doit etre WW:=d(3,3) + d(1,1)$ on resout l'equation {{1,6},4} qui est maintenant AA:=d(2,6) + d(0,1)$ Unknowns: {d(2,6),d(0,1)} Unknowns: {d(2,6),d(0,1)} bonne inconnue W:=d(2,6)$ sa valeur doit etre WW:= - d(0,1)$ on resout l'equation {{1,6},5} qui est maintenant AA:=d(3,6)$ Unknown: d(3,6) Unknown: d(3,6) bonne inconnue W:=d(3,6)$ sa valeur doit etre WW:=0$ on resout l'equation {{2,3},4} qui est maintenant AA:= - d(1,3)$ Unknown: d(1,3) Unknown: d(1,3) bonne inconnue W:=d(1,3)$ sa valeur doit etre WW:=0$ on resout l'equation {{2,3},5} qui est maintenant AA:=d(1,2)$ Unknown: d(1,2) Unknown: d(1,2) bonne inconnue W:=d(1,2)$ sa valeur doit etre WW:=0$ on resout l'equation {{2,6},4} qui est maintenant AA:= - d(1,6) + d(0,2)$ Unknowns: {d(1,6),d(0,2)} Unknowns: {d(1,6),d(0,2)} bonne inconnue W:=d(1,6)$ sa valeur doit etre WW:=d(0,2)$ on resout l'equation {{3,6},4} qui est maintenant AA:=d(0,3)$ Unknown: d(0,3) Unknown: d(0,3) bonne inconnue W:=d(0,3)$ sa valeur doit etre WW:=0$ on resout l'equation {{3,6},5} qui est maintenant AA:= - d(0,2)$ Unknown: d(0,2) Unknown: d(0,2) bonne inconnue W:=d(0,2)$ sa valeur doit etre WW:=0$ Derivation equations to cancel (Reduce output) : \\{{{{0,1},4},0}, {{{0,1},5},0}, {{{0,2},4},0}, {{{0,3},4},0}, {{{0,3},5},0}, {{{0,4},4},0}, {{{0,5},4},0}, {{{0,6},0},0}, {{{0,6},1},0}, {{{0,6},2},0}, {{{0,6},3},0}, {{{0,6},4},0}, {{{0,6},5},0}, {{{0,6},6},0}, {{{1,2},0},0}, {{{1,2},1},0}, {{{1,2},2},0}, {{{1,2},3},0}, {{{1,2},4},0}, {{{1,2},5},0}, {{{1,2},6},0}, {{{1,3},0},0}, {{{1,3},1},0}, {{{1,3},2},0}, {{{1,3},3},0}, {{{1,3},4},0}, {{{1,3},5},0}, {{{1,3},6},0}, {{{1,4},4},0}, {{{1,4},5},0}, {{{1,5},4},0}, {{{1,5},5},0}, {{{1,6},4},0}, {{{1,6},5},0}, {{{2,3},4},0}, {{{2,3},5},0}, {{{2,4},4},0}, {{{2,5},4},0}, {{{2,6},4},0}, {{{3,4},5},0}, {{{3,5},5},0}, {{{3,6},4},0}, {{{3,6},5},0}, {{{4,6},4},0}, {{{5,6},4},0}}$ Il n'y a pas de phase 2$ derivation generique de gtildedelta:$ MATD:= mat((d(0,0),d(0,1),0,0,0,0,d(0,6)),(0,d(1,1),0,0,0,0,0),(d(2,0),d(2,1),d(2,2),d( 2,3),0,0, - d(0,1)),(0,d(3,1),0,d(3,3),0,0,0),(d(4,0),d(4,1),d(4,2),d(4,3),d(2,2 ) + d(1,1),d(2,3),d(4,6)),(d(5,0),d(5,1),d(5,2),d(5,3),0,d(3,3) + d(1,1),d(5,6)) ,(d(6,0),d(2,0),0,0,0,0,d(2,2) + d(1,1) - d(0,0)))$ pour delta:= [0 0 0 0 0 0] [ ] [0 0 0 0 0 0] [ ] [0 0 0 0 0 0] [ ] [0 0 0 0 0 1] [ ] [0 0 0 0 0 0] [ ] [0 0 0 0 0 0] pour shortformdelta:={0,0,0,ss,0,0,ss,0,0,0,ss,1,0} Unknowns: {d(6,0), d(5,6), d(5,3), d(5,2), d(5,1), d(5,0), d(4,6), d(4,3), d(4,2), d(4,1), d(4,0), d(3,3), d(3,1), d(2,3), d(2,2), d(2,1), d(2,0), d(1,1), d(0,6), d(0,1), d(0,0)} Unknowns: {d(6,0), d(5,6), d(5,3), d(5,2), d(5,1), d(5,0), d(4,6), d(4,3), d(4,2), d(4,1), d(4,0), d(3,3), d(3,1), d(2,3), d(2,2), d(2,1), d(2,0), d(1,1), d(0,6), d(0,1), d(0,0)} listeparametresMATD{d(6,0), d(5,6), d(5,3), d(5,2), d(5,1), d(5,0), d(4,6), d(4,3), d(4,2), d(4,1), d(4,0), d(3,3), d(3,1), d(2,3), d(2,2), d(2,1), d(2,0), d(1,1), d(0,6), d(0,1), d(0,0)}$ dim Der(gtildedelta):=21$ t1:=D(0,0):= [1 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 -1] Unknowns: {d(5,3), d(5,2), d(5,1), d(4,3), d(4,2), d(4,1), d(3,3), d(3,1), d(2,3), d(2,2), d(2,1), d(1,1), d(0,0)} Unknowns: {d(5,3), d(5,2), d(5,1), d(4,3), d(4,2), d(4,1), d(3,3), d(3,1), d(2,3), d(2,2), d(2,1), d(1,1), d(0,0)} t2:=D(1,1):= [0 0 0 0 0 0 0] [ ] [0 1 0 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 1 0 0] [ ] [0 0 0 0 0 1 0] [ ] [0 0 0 0 0 0 1] Unknowns: {d(5,1),d(4,1),d(3,3),d(2,3),d(2,2),d(1,1),d(0,0)} Unknowns: {d(5,1),d(4,1),d(3,3),d(2,3),d(2,2),d(1,1),d(0,0)} t3:=D(2,2):= [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 1 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 1 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 0 1] MATD:= mat((d(0,0),0,0,0,0,0,0), (0,d(1,1),0,0,0,0,0), (0,0,d(2,2),0,0,0,0), (0,0,0,d(3,3),0,0,0), (0,0,0,0,d(2,2) + d(1,1),0,0), (0,d(5,1),0,0,0,d(3,3) + d(1,1),0), (0,0,0,0,0,0,d(2,2) + d(1,1) - d(0,0))) Unknowns: {d(5,1),d(3,3),d(2,2),d(1,1),d(0,0)} Unknowns: {d(5,1),d(3,3),d(2,2),d(1,1),d(0,0)} Unknowns: {d(5,1),d(3,3),d(2,2),d(1,1),d(0,0)} Unknowns: {d(5,1),d(3,3),d(2,2),d(1,1),d(0,0)} t4:=D(3,3):= [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 1 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 1 0] [ ] [0 0 0 0 0 0 0] Unknowns: {d(3,3),d(2,2),d(1,1),d(0,0)} Unknowns: {d(3,3),d(2,2),d(1,1),d(0,0)} commutant simultane de t1,t2,t3,t4 dans der(gtildedelta): mat((d(0,0),0,0,0,0,0,0), (0,d(1,1),0,0,0,0,0), (0,0,d(2,2),0,0,0,0), (0,0,0,d(3,3),0,0,0), (0,0,0,0,d(2,2) + d(1,1),0,0), (0,0,0,0,0,d(3,3) + d(1,1),0), (0,0,0,0,0,0,d(2,2) + d(1,1) - d(0,0))) rank 4 with maximal torus t1,t2,t3,t4 4 matrice de passage de la base X(0)=delta, X(1),..., X(6) a une base diagonali\ sant le tore maximal: on peut prendre P:= [1 0 0 0 0 0 0] [ ] [0 1 0 0 0 0 0] [ ] [0 0 1 0 0 0 0] [ ] [0 0 0 1 0 0 0] [ ] [0 0 0 0 1 0 0] [ ] [0 0 0 0 0 1 0] [ ] [0 0 0 0 0 0 1] P**(-1)*t1*P:= [1 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 0 ] [ ] [0 0 0 0 0 0 -1] P**(-1)*t2*P:= [0 0 0 0 0 0 0] [ ] [0 1 0 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 1 0 0] [ ] [0 0 0 0 0 1 0] [ ] [0 0 0 0 0 0 1] P**(-1)*t3*P:= [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 1 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 1 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 0 1] P**(-1)*t4*P:= [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 1 0 0 0] [ ] [0 0 0 0 0 0 0] [ ] [0 0 0 0 0 1 0] [ ] [0 0 0 0 0 0 0] matrice des derivations dans cette base diagonalisante Y(1),...,Y(7): P**(-1)*MATD*P:= mat((d(0,0),d(0,1),0,0,0,0,d(0,6)),(0,d(1,1),0,0,0,0,0),(d(2,0),d(2,1),d(2,2),d( 2,3),0,0, - d(0,1)),(0,d(3,1),0,d(3,3),0,0,0),(d(4,0),d(4,1),d(4,2),d(4,3),d(2,2 ) + d(1,1),d(2,3),d(4,6)),(d(5,0),d(5,1),d(5,2),d(5,3),0,d(3,3) + d(1,1),d(5,6)) ,(d(6,0),d(2,0),0,0,0,0,d(2,2) + d(1,1) - d(0,0)))$ PP:= [1 0 0 0 0 0 0] [ ] [0 1 0 0 0 0 0] [ ] [0 0 1 0 0 0 0] [ ] [0 0 0 1 0 0 0] [ ] [0 0 0 0 1 0 0] [ ] [0 0 0 0 0 1 0] [ ] [0 0 0 0 0 0 1] avec PP:=P*Q:= [1 0 0 0 0 0 0] [ ] [0 1 0 0 0 0 0] [ ] [0 0 1 0 0 0 0] [ ] [0 0 0 1 0 0 0] [ ] [0 0 0 0 1 0 0] [ ] [0 0 0 0 0 1 0] [ ] [0 0 0 0 0 0 1] MATDDIAGONALISE:= mat((d(0,0),d(0,1),0,0,0,0,d(0,6)), (0,d(1,1),0,0,0,0,0), (d(2,0),d(2,1),d(2,2),d(2,3),0,0, - d(0,1)), (0,d(3,1),0,d(3,3),0,0,0), (d(4,0),d(4,1),d(4,2),d(4,3),d(2,2) + d(1,1),d(2,3),d(4,6)), (d(5,0),d(5,1),d(5,2),d(5,3),0,d(3,3) + d(1,1),d(5,6)), (d(6,0),d(2,0),0,0,0,0,d(2,2) + d(1,1) - d(0,0))) on voit apparaitre les poids sur la diagonale r(1) := d(0,0) r(2) := d(1,1) r(3) := d(2,2) r(4) := d(3,3) r(5) := d(2,2) + d(1,1) r(6) := d(3,3) + d(1,1) r(7) := d(2,2) + d(1,1) - d(0,0) r(1) := gamma1 r(2) := gamma2 - gamma3 + gamma1 r(3) := gamma3 r(4) := gamma4 r(5) := gamma1 + gamma2 r(6) := gamma2 - gamma3 + gamma1 + gamma4 r(7) := gamma2 Le systeme de poids est le systeme 4.3 calcul de relations de commutation de la base diaY(j) diagonalisant le tore listcommutateursdesx := {{{0,1},0}, {{0,2},0}, {{0,3},0}, {{0,4},0}, {{0,5},0}, {{0,6},x(4)}, {{1,2},x(4)}, {{1,3},x(5)}, {{1,4},0}, {{1,5},0}, {{1,6},0}, {{2,3},0}, {{2,4},0}, {{2,5},0}, {{2,6},0}, {{3,4},0}, {{3,5},0}, {{3,6},0}, {{4,5},0}, {{4,6},0}, {{5,6},0}} diaY(1):=x(0) diaY(2):=x(1) diaY(3):=x(2) diaY(4):=x(3) diaY(5):=x(4) diaY(6):=x(5) diaY(7):=x(6) liste des commutateurs des diaY(i) :$ listcommutateurdesdiaY:={{{1,2},0}, {{1,3},0}, {{1,4},0}, {{1,5},0}, {{1,6},0}, {{1,7},diay(5)}, {{2,3},diay(5)}, {{2,4},diay(6)}, {{2,5},0}, {{2,6},0}, {{2,7},0}, {{3,4},0}, {{3,5},0}, {{3,6},0}, {{3,7},0}, {{4,5},0}, {{4,6},0}, {{4,7},0}, {{5,6},0}, {{5,7},0}, {{6,7},0}}$ Now we make explicit the isomorphism with an algebra of the book:$ Namely g_{7,4.3}$ i.e. we go from the basis diaY(i) to the new basis ZZ(i) defined by the matrix:$ on pose :$ avec comme matrice de changement de base :$ mat((1,0,0,0,0,0,0),(0,0,0,0,1,0,0),(0,0,-1,0,0,0,0),(0,0,0,-1,0,0,0),(0,0,0,0,0 ,1,0),(0,0,0,0,0,0,1),(0,1,0,0,0,0,0))$ det(isom):= -1$ ZZ(1):=diay(1)$ ZZ(2):=diay(7)$ ZZ(3):= - diay(3)$ ZZ(4):= - diay(4)$ ZZ(5):=diay(2)$ ZZ(6):=diay(5)$ ZZ(7):=diay(6)$ listcommutateursdesZZ:=$ {{1,2},zz(6)}$ {{1,3},0}$ {{1,4},0}$ {{1,5},0}$ {{1,6},0}$ {{1,7},0}$ {{2,3},0}$ {{2,4},0}$ {{2,5},0}$ {{2,6},0}$ {{2,7},0}$ {{3,4},0}$ {{3,5},zz(6)}$ {{3,6},0}$ {{3,7},0}$ {{4,5},zz(7)}$ {{4,6},0}$ {{4,7},0}$ {{5,6},0}$ {{5,7},0}$ {{6,7},0}$ We get the commutation relations of$ g_{7,4.3}$ Et cela pour a:=0, b:=0.$ shortformdelta:={0,0,0,ss,0,0,ss,0,0,0,ss,1,0}$ delta:= mat((0,0,0,0,0,0),(0,0,0,0,0,0),(0,0,0,0,0,0),(0,0,0,0,0,1),(0,0,0,0,0,0),(0,0,0 ,0,0,0))$