R:= RootSystem( "A",6); U:=QuantizedUEA(R); g:= GeneratorsOfAlgebra( U ); PositiveRoots(R); PositiveRootsInConvexOrder(R); ########## generators of U ############### f1:=g[1]; f2:=g[3]; f3:=g[6]; f4:=g[10]; f5:=g[15]; f6:=g[21]; e1:=g[34]; e2:=g[36]; e3:=g[39]; e4:=g[43]; e5:=g[48]; e6:=g[54]; k1:=g[22]; k2:=g[24]; k3:=g[26]; k4:=g[28]; k5:=g[30]; k6:=g[32]; k1m:=g[23]; k2m:=g[25]; k3m:=g[27]; k4m:=g[29]; k5m:=g[31]; k6m:=g[33]; ########## generators of B ############### b1:=f1 - k1m * e6; b2:=f2 - k2m * e5; b3:=f3 - k3m * e4; b4:=f4 - k4m * e3; b5:=f5 - k5m * e2; b6:=f6 - k6m * e1; a1:= k1 * k6m; a2:= k2 * k5m; a3:= k3 * k4m; a4:= k4 * k3m; a5:= k5 * k2m; a6:= k6 * k1m; ########## q-numbers #################### 2q:=_q+_q^-1; ########## q-commutator ################# qcom:=function(a,b) return a*b-_q*b*a; end; ######### relations in B as a function ######### rel1:=function(a,b) return a^2*b - (_q + _q^-1)*a*b*a + b*a^2 ; end; ################# relations #################### (_q-_q^-1)*(b1 * b6 - b6 * b1) - a1 + a6; (_q-_q^-1)*(b2 * b5 - b5 * b2) - a2 + a5; rel1(b1,b2); rel1(b2,b1); b1 *b3 - b3* b1; b2 * b4 - b4 * b2; rel1(b2,b3); rel1(b3,b2); rel1(b3,b4) - 2q * b3 *( _q^2* a4 + _q^-1 * a3); #### from here onwards it's symmetric rel1(b4,b3) - 2q * b4 *( _q^2* a3 + _q^-1 * a4); rel1(b4,b5); rel1(b5,b4); b5 *b3 - b3* b5; b6 * b4 - b4 * b6; rel1(b5,b6); rel1(b6,b5); ################# \tau_3^- braid group action ##################### t3mb1:=b1;; t3mb2:=_q^-2*qcom(b4,qcom(b3,b2)) + a4 * b2;; ##### times _q^(1/2) t3mb3:= _q^-2 * a4 * b3;; ##### times _q^(1/2) t3mb4:= _q^-2 * a3 * b4;; ##### times _q^(1/2) t3mb5:=_q^-2*qcom(b3,qcom(b4,b5)) + a3 * b5;; ##### times _q^(1/2) t3mb6:=b6;; t3ma1:=a1;; t3ma2:=a2;; t3ma3:=a3;; t3ma4:=a4;; t3ma5:=a5;; t3ma6:=a6;; ################# t3m is an algebra homomorphism ############ (_q-_q^-1)*(t3mb1 * t3mb6 - t3mb6 * t3mb1) - t3ma1 + t3ma6; (_q-_q^-1)* _q *(t3mb2 * t3mb5 - t3mb5 * t3mb2) - t3ma2 + t3ma5; rel1(t3mb1,t3mb2); rel1(t3mb2,t3mb1); t3mb1 *t3mb3 - t3mb3* t3mb1; t3mb2 * t3mb4 - t3mb4 * t3mb2; rel1(t3mb2,t3mb3); rel1(t3mb3,t3mb2); _q * rel1(t3mb3,t3mb4) - 2q * t3mb3 *( _q^2* t3ma4 + _q^-1 * t3ma3); #### from here onwards it's symmetric ################# the inverse \tau_3 of \tau_3^- ################## t3b1:=b1;; t3b2:=_q^-1*qcom(qcom(b2,b3),b4) + a3 * b2;; ##### times _q^(-1/2) t3b3:=_q^2 * a3 * b3;; ##### times _q^(-1/2) t3b4:=_q^2 * a4 * b4;; ##### times _q^(-1/2) t3b5:=_q^-1*qcom(qcom(b5,b4),b3) + a4 * b5;; ##### times _q^(-1/2) t3b6:=b6;; t3a1:=a1;; t3a2:=a2;; t3a3:=a3;; t3a4:=a4;; t3a5:=a5;; t3a6:=a6;; ################ t3 is an algebra homomorphism ################ (_q-_q^-1)*(t3b1 * t3b6 - t3b6 * t3b1) - t3a1 + t3a6; (_q-_q^-1)* _q^-1 *(t3b2 * t3b5 - t3b5 * t3b2) - t3a2 + t3a5; rel1(t3b1,t3b2); rel1(t3b2,t3b1); t3b1 *t3b3 - t3b3* t3b1; t3b2 * t3b4 - t3b4 * t3b2; rel1(t3b2,t3b3); rel1(t3b3,t3b2); _q^-1 * rel1(t3b3,t3b4) - 2q * t3b3 *( _q^2* t3a4 + _q^-1 * t3a3); #### from here onwards it's symmetric ########### t3 is the inverse of t3m #################### qcom(qcom(t3mb2,t3mb3),t3mb4) + t3ma3 * t3mb2 - b2; _q^2 * t3ma3 * t3mb3 - b3; _q^2 * t3ma4 * t3mb4 - b4; qcom(qcom(t3mb5,t3mb4),t3mb3) + t3ma4 * t3mb5 - b5; _q^-3*qcom(t3b4,qcom(t3b3,t3b2)) + t3a4 * t3b2 - b2; _q^-2 * t3a4 * t3b3 - b3; _q^-2 * t3a3 * t3b4 - b4; _q^-3*qcom(t3b3,qcom(t3b4,t3b5)) + t3a3 * t3b5 - b5; ############ \tau_2^- braid group action #################### t2mb1:=qcom(b2,b1);; #### times _q^(-1/2) t2mb2:= _q^-1*a2 * b5;; t2mb3:=qcom(b2,b3);; #### times _q^(-1/2) t2mb4:=qcom(b5,b4);; #### times _q^(-1/2) t2mb5:= _q^-1 * a5 *b2;; t2mb6:=qcom(b5,b6);; #### times _q^(-1/2) t2ma1:= a1 * a2;; t2ma2:= a5;; t2ma3:= a2 * a3;; t2ma4:= a5 * a4;; t2ma5:= a2;; t2ma6:= a6 * a5;; ################# t2m is an algebra homomorphism ############ (_q-_q^-1)*_q^-1 * (t2mb1 * t2mb6 - t2mb6 * t2mb1) - t2ma1 + t2ma6; (_q-_q^-1)*(t2mb2 * t2mb5 - t2mb5 * t2mb2) - t2ma2 + t2ma5; rel1(t2mb1,t2mb2); rel1(t2mb2,t2mb1); t2mb1 *t2mb3 - t2mb3* t2mb1; t2mb2 * t2mb4 - t2mb4 * t2mb2; rel1(t2mb2,t2mb3); rel1(t2mb3,t2mb2); _q^-1 *rel1(t2mb3,t2mb4) - 2q * t2mb3 *( _q^2* t2ma4 + _q^-1 * t2ma3); #### from here onwards it's symmetric ########### the inverse \tau_2 of \tau_2^- ################# t2b1:= qcom(b1,b2);; #### times _q^(-1/2) t2b2:= _q *a5 * b5;; t2b3:= qcom(b3,b2);; #### times _q^(-1/2) t2b4:= qcom(b4,b5);; #### times _q^(-1/2) t2b5:= _q * a2 *b2;; t2b6:= qcom(b6,b5);; #### times _q^(-1/2) t2a1:= a1 * a2;; t2a2:= a5;; t2a3:= a2 * a3;; t2a4:= a4 * a5;; t2a5:= a2;; t2a6:= a6 * a5;; ################# t2 is an algebra homomorphism ############ (_q-_q^-1)*_q^-1 * (t2b1 * t2b6 - t2b6 * t2b1) - t2a1 + t2a6; (_q-_q^-1)*(t2b2 * t2b5 - t2b5 * t2b2) - t2a2 + t2a5; rel1(t2b1,t2b2); rel1(t2b2,t2b1); t2b1 * t2b3 - t2b3 * t2b1; t2b2 * t2b4 - t2b4 * t2b2; rel1(t2b2,t2b3); rel1(t2b3,t2b2); _q^-1 * rel1(t2b3,t2b4) - 2q * t2b3 *( _q^2* t2a4 + _q^-1 * t2a3); #### from here onwards it's symmetric ########### t2m is the inverse of t2 ##################### _q^-1 * qcom(t2b2,t2b1) - b1; _q^-1 * t2a2 * t2b5 - b2; _q^-1 * qcom(t2b2,t2b3) - b3; _q^-1 * qcom(t2b5,t2b4) - b4; _q^-1 * t2a5 *t2b2 - b5; _q^-1 * qcom(t2b5,t2b6) - b6; t2a1 * t2a2 - a1; t2a5 - a2; t2a2 * t2a3 - a3; t2a5 * t2a4 - a4; t2a2 - a5; t2a6 * t2a5 - a6; ############ \tau_1^- braid group action #################### t1mb1:= _q^-1 * a1 * b6;; t1mb2:=qcom(b1,b2);; #### times _q^(-1/2); t1mb3:=b3;; t1mb4:=b4;; t1mb5:=qcom(b6,b5);; #### times _q^(-1/2); t1mb6:= _q^-1 * a6 * b1;; t1ma1:= a6;; t1ma2:= a1 * a2;; t1ma3:= a3;; t1ma4:= a4;; t1ma5:= a6 * a5;; t1ma6:= a1;; ################# t1m is an algebra homomorphism ############ (_q-_q^-1) * (t1mb1 * t1mb6 - t1mb6 * t1mb1) - t1ma1 + t1ma6; (_q-_q^-1)* _q^-1 *(t1mb2 * t1mb5 - t1mb5 * t1mb2) - t1ma2 + t1ma5; rel1(t1mb1,t1mb2); rel1(t1mb2,t1mb1); t1mb1 *t1mb3 - t1mb3* t1mb1; t1mb2 * t1mb4 - t1mb4 * t1mb2; rel1(t1mb2,t1mb3); rel1(t1mb3,t1mb2); rel1(t1mb3,t1mb4) - 2q * t1mb3 *( _q^2* t1ma4 + _q^-1 * t1ma3); #### from here onwards it's symmetric ########### the inverse \tau_1 of \tau_1^- ################# t1b1:= _q * a6 * b6;; t1b2:=qcom(b2,b1);; #### times _q^(-1/2); t1b3:=b3;; t1b4:=b4;; t1b5:=qcom(b5,b6);; #### times _q^(-1/2); t1b6:= _q * a1 * b1;; t1a1:= a6;; t1a2:= a1 * a2;; t1a3:= a3;; t1a4:= a4;; t1a5:= a6 * a5;; t1a6:= a1;; ################# t1 is an algebra homomorphism ############ (_q-_q^-1) * (t1b1 * t1b6 - t1b6 * t1b1) - t1a1 + t1a6; (_q-_q^-1) * _q^-1 *(t1b2 * t1b5 - t1b5 * t1b2) - t1a2 + t1a5; rel1(t1b1,t1b2); rel1(t1b2,t1b1); t1b1 * t1b3 - t1b3 * t1b1; t1b2 * t1b4 - t1b4 * t1b2; rel1(t1b2,t1b3); rel1(t1b3,t1b2); rel1(t1b3,t1b4) - 2q * t1b3 *( _q^2* t1a4 + _q^-1 * t1a3); #### from here onwards it's symmetric ################ t1 is the inverse of t1m ################## _q * t1ma6 * t1mb6 - b1; _q^-1 * qcom(t1mb2,t1mb1)-b2; _q^-1 * qcom(t1mb5,t1mb6)-b5; _q * t1ma1 * t1mb1 - b6; _q^-1 * t1a1 * t1b6 - b1; _q^-1 * qcom(t1b1,t1b2) - b2; _q^-1 * qcom(t1b6,t1b5) - b5; _q^-1 * t1a6 * t1b1 - b6; ############################################################# ################ Verifying the braid relation ############### ################ t2 t1 t2 = t1 t2 t1 ############### ############################################################# t21b1:= _q * t2a6 * t2b6;; #### times _q^(-1/2); t21b2:=qcom(t2b2,t2b1);; #### times _q^(-1); t21b3:=t2b3;; #### times _q^(-1/2); t21b4:=t2b4;; #### times _q^(-1/2); t21b5:=qcom(t2b5,t2b6);; #### times _q^(-1); t21b6:= _q * t2a1 * t2b1;; #### times _q^(-1/2); t21a1:= t2a6;; t21a2:= t2a1 * t2a2;; t21a3:= t2a3;; t21a4:= t2a4;; t21a5:= t2a6 * t2a5;; t21a6:= t2a1;; ##### t12b1:= qcom(t1b1,t1b2);; #### times _q^(-1) t12b2:= _q *t1a5 * t1b5;; #### times _q^(-1/2) t12b3:= qcom(t1b3,t1b2);; #### times _q^(-1) t12b4:= qcom(t1b4,t1b5);; #### times _q^(-1) t12b5:= _q * t1a2 *t1b2;; #### times _q^(-1/2) t12b6:= qcom(t1b6,t1b5);; #### times _q^(-1) t12a1:= t1a1 * t1a2;; t12a2:= t1a5;; t12a3:= t1a2 * t1a3;; t12a4:= t1a4 * t1a5;; t12a5:= t1a2;; t12a6:= t1a6 * t1a5;; ##### t121b1:= _q * t12a6 * t12b6;; #### times _q^(-1); t121b2:=qcom(t12b2,t12b1);; #### times _q^(-2); t121b3:=t12b3;; #### times _q^(-1); t121b4:=t12b4;; #### times _q^(-1); t121b5:=qcom(t12b5,t12b6);; #### times _q^(-2); t121b6:= _q * t12a1 * t12b1;; #### times _q^(-1); ##### t212b1:= qcom(t21b1,t21b2);; #### times _q^(-2) t212b2:= _q *t21a5 * t21b5;; #### times _q^(-1) t212b3:= qcom(t21b3,t21b2);; #### times _q^(-2) t212b4:= qcom(t21b4,t21b5);; #### times _q^(-2) t212b5:= _q * t21a2 *t21b2;; #### times _q^(-1) t212b6:= qcom(t21b6,t21b5);; #### times _q^(-2) ############# final check ################################### t121b1 - _q^-1 * t212b1; _q^-1 * t121b2 - t212b2; t121b3 - _q^-1 * t212b3; t121b4 - _q^-1 * t212b4; _q^-1 * t121b5 - t212b5; t121b6 - _q^-1 * t212b6; ############################################################# ################ Verifying the braid relation ############### ################ t2 t3 t2 t3 = t3 t2 t3 t2 ############### ############################################################# t3b1:=b1;; t3b2:=_q^-1*qcom(qcom(b2,b3),b4) + a3 * b2;; ##### times _q^(-1/2) t3b3:=_q^2 * a3 * b3;; ##### times _q^(-1/2) t3b4:=_q^2 * a4 * b4;; ##### times _q^(-1/2) t3b5:=_q^-1*qcom(qcom(b5,b4),b3) + a4 * b5;; ##### times _q^(-1/2) t3b6:=b6;; t3a1:=a1;; t3a2:=a2;; t3a3:=a3;; t3a4:=a4;; t3a5:=a5;; t3a6:=a6;; ############## t2b1:= qcom(b1,b2);; #### times _q^(-1/2) t2b2:= _q *a5 * b5;; t2b3:= qcom(b3,b2);; #### times _q^(-1/2) t2b4:= qcom(b4,b5);; #### times _q^(-1/2) t2b5:= _q * a2 *b2;; t2b6:= qcom(b6,b5);; #### times _q^(-1/2) t2a1:= a1 * a2;; t2a2:= a5;; t2a3:= a2 * a3;; t2a4:= a4 * a5;; t2a5:= a2;; t2a6:= a6 * a5;; ############## t23b1:=t2b1;; #### times _q^(-1/2) t23b2:=_q^-2*qcom(qcom(t2b2,t2b3),t2b4) + t2a3 * t2b2;; ##### times _q^(-1/2) t23b3:=_q * t2a3 * t2b3;; t23b4:=_q * t2a4 * t2b4;; t23b5:=_q^-2*qcom(qcom(t2b5,t2b4),t2b3) + t2a4 * t2b5;; ##### times _q^(-1/2) t23b6:=t2b6;; #### times _q^(-1/2) t23a1:=t2a1;; t23a2:=t2a2;; t23a3:=t2a3;; t23a4:=t2a4;; t23a5:=t2a5;; t23a6:=t2a6;; ############## t32b1:= _q^-1 * qcom(t3b1,t3b2);; t32b2:= _q *t3a5 * t3b5;; #### times _q^(-1/2) t32b3:= _q^-1 * qcom(t3b3,t3b2);; #### times _q^(-1/2) t32b4:= _q^-1 * qcom(t3b4,t3b5);; #### times _q^(-1/2) t32b5:= _q * t3a2 *t3b2;; #### times _q^(-1/2) t32b6:= _q^-1 * qcom(t3b6,t3b5);; t32a1:= t3a1 * t3a2;; t32a2:= t3a5;; t32a3:= t3a2 * t3a3;; t32a4:= t3a4 * t3a5;; t32a5:= t3a2;; t32a6:= t3a6 * t3a5;; ############## t323b1:=t32b1;; #### times _q^(-1/2) t323b2:=_q^-3*qcom(qcom(t32b2,t32b3),t32b4) + _q^-1 * t32a3 * t32b2;; t323b3:=_q * t32a3 * t32b3;; t323b4:=_q * t32a4 * t32b4;; t323b5:=_q^-3*qcom(qcom(t32b5,t32b4),t32b3) + _q^-1 * t32a4 * t32b5;; t323b6:=t32b6;; #### times _q^(-1/2) t323a1:=t32a1;; t323a2:=t32a2;; t323a3:=t32a3;; t323a4:=t32a4;; t323a5:=t32a5;; t323a6:=t32a6;; ############## t232b1:= _q^-1 * qcom(t23b1,t23b2);; #### times _q^(-1/2) t232b2:= _q *t23a5 * t23b5;; #### times _q^(-1/2) t232b3:= _q^-1 * qcom(t23b3,t23b2);; t232b4:= _q^-1 * qcom(t23b4,t23b5);; t232b5:= _q * t23a2 *t23b2;; #### times _q^(-1/2) t232b6:= _q^-1 * qcom(t23b6,t23b5);; #### times _q^(-1/2) t232a1:= t23a1 * t23a2;; t232a2:= t23a5;; t232a3:= t23a2 * t23a3;; t232a4:= t23a4 * t23a5;; t232a5:= t23a2;; t232a6:= t23a6 * t23a5;; ############## t2323b1:=t232b1;; #### times _q^-1 t2323b2:=_q^-2*qcom(qcom(t232b2,t232b3),t232b4) + _q^-1 * t232a3 * t232b2;; t2323b3:=_q * t232a3 * t232b3;; #### times _q^(1/2) t2323b4:=_q * t232a4 * t232b4;; #### times _q^(1/2) t2323b5:=_q^-2*qcom(qcom(t232b5,t232b4),t232b3) + _q^-1 * t232a4 * t232b5;; t2323b6:=t232b6;; #### times _q^-1 t2323a1:=t232a1;; t2323a2:=t232a2;; t2323a3:=t232a3;; t2323a4:=t232a4;; t2323a5:=t232a5;; t2323a6:=t232a6;; ############## t3232b1:= _q^-1 * qcom(t323b1,t323b2);; t3232b2:= _q *t323a5 * t323b5;; t3232b3:= _q^-1 * qcom(t323b3,t323b2);; #### times _q^(1/2) t3232b4:= _q^-1 * qcom(t323b4,t323b5);; #### times _q^(1/2) t3232b5:= _q * t323a2 *t323b2;; t3232b6:= _q^-1 * qcom(t323b6,t323b5);; t3232a1:= t323a1 * t323a2;; t3232a2:= t323a5;; t3232a3:= t323a2 * t323a3;; t3232a4:= t323a4 * t323a5;; t3232a5:= t323a2;; t3232a6:= t323a6 * t323a5;; ############ final check ################## t3232b1 - _q^-1 * t2323b1; t3232b2 - t2323b2; t3232b3 - t2323b3; t3232b4 - t2323b4; t3232b5 - t2323b5; t3232b6 - _q^-1 * t2323b6; ####################### ####### :-) End :-) #####################################