R:= RootSystem( "C",3); U:=QuantizedUEA(R); g:= GeneratorsOfAlgebra( U ); PositiveRoots(R); PositiveRootsInConvexOrder(R); ########## generators of U ############### f1:=g[1]; f2:=g[3]; f3:=g[9]; e1:=g[16]; e2:=g[18]; e3:=g[24]; k1:=g[10]; k1m:=g[11]; k2:=g[12]; k2m:=g[13]; k3:=g[14]; k3m:=g[15]; ########## generators of Uq'(k) ############### b1:=f1-k1m*e1; b2:=f2-k2m*e2; b3:=f3-k3m*e3; ########## q-numbers #################### 2q:=_q+_q^-1; 3q:=_q^2+1+_q^-2; ######### relations in Uq'(k) as functions ######### rel0:=function(a,b) return a*b - b*a; end; rel1:=function(a,b) return a^2*b - (_q+_q^-1)*a*b*a + b*a^2 +_q^-1 *b; end; rel12:=function(a,b) return a^2*b - (_q^2+_q^-2)*a*b*a + b*a^2 +_q^-2 *b; end; rel2:=function(a,b) return b^3*a - 3q *b^2*a*b + 3q* b*a*b^2 - a*b^3 +_q^-1*2q^2 *(b*a-a*b); end; ############################################################################### ########### We check that the generators bi really satisfy the relations ###### ########### given Proposition 3.1 ###### ############################################################################### rel0(b1,b3); rel1(b1,b2); rel1(b2,b1); rel12(b3,b2); rel2(b3,b2); ######## Definition of \tau_1^- ########## tau1mb1 := b1;; tau1mb2 := b1*b2 - _q *b2*b1;; tau1mb3 := b3;; ####### \tau_1^- is an algebra homomorphism ##### rel0(tau1mb1,tau1mb3); rel1(tau1mb1,tau1mb2); rel1(tau1mb2,tau1mb1); rel12(tau1mb3,tau1mb2); rel2(tau1mb3,tau1mb2); ######## Definition of \tau_1 ########## tau1b1 := b1;; tau1b2 := b2*b1 - _q *b1*b2;; tau1b3 := b3;; ####### \tau_1 is an algebra homomorphism ##### rel0(tau1b1,tau1b3); rel1(tau1b1,tau1b2); rel1(tau1b2,tau1b1); rel12(tau1b3,tau1b2); rel2(tau1b3,tau1b2); ###### \tau_1 is the inverse of \tau_1^- ##### tau1b1*tau1b2 - _q *tau1b2*tau1b1 - b2; tau1mb2*tau1mb1 - _q *tau1mb1*tau1mb2 -b2; ######## Definition of \tau_2^- ########## tau2mb1 := b2*b1-_q * b1*b2;; tau2mb2 := b2;; tau2mb3 := 2q^-1*b2^2*b3-_q*b2*b3*b2+_q^2*2q^-1*b3*b2^2+ b3;; ####### \tau_2^- is an algebra homomorphism ##### rel0(tau2mb1,tau2mb3); rel1(tau2mb1,tau2mb2); rel1(tau2mb2,tau2mb1); rel12(tau2mb3,tau2mb2); rel2(tau2mb3,tau2mb2); ######## Definition of \tau_2 ########## tau2b1 := b1*b2-_q * b2*b1;; tau2b2 := b2;; tau2b3 := 2q^-1*b3*b2^2 -_q*b2*b3*b2+_q^2*2q^-1*b2^2*b3 + b3;; ####### \tau_2 is an algebra homomorphism ##### rel0(tau2b1,tau2b3); rel1(tau2b1,tau2b2); rel1(tau2b2,tau2b1); rel12(tau2b3,tau2b2); rel2(tau2b3,tau2b2); ####### \tau_2 is the inverse of \tau_2^- ######### tau2b2*tau2b1-_q * tau2b1*tau2b2 -b1; 2q^-1*tau2b2^2*tau2b3-_q*tau2b2*tau2b3*tau2b2+_q^2*2q^-1*tau2b3*tau2b2^2+ tau2b3 -b3; tau2mb1*tau2mb2-_q * tau2mb2*tau2mb1 -b1; 2q^-1*tau2mb3*tau2mb2^2 -_q*tau2mb2*tau2mb3*tau2mb2+_q^2*2q^-1*tau2mb2^2*tau2mb3 + tau2mb3-b3; ######## Definition of \tau_3^- ########################## tau3mb1 := b1;; tau3mb2 := b3 * b2 - _q^2 * b2 * b3;; tau3mb3 := b3;; ####### \tau_3^- is an algebra homomorphism ##### rel0(tau3mb1,tau3mb3); rel1(tau3mb1,tau3mb2); rel1(tau3mb2,tau3mb1); rel12(tau3mb3,tau3mb2); rel2(tau3mb3,tau3mb2); ######## Definition of \tau_3 ########################## tau3b1 := b1;; tau3b2 := b2 * b3 - _q^2 * b3 * b2;; tau3b3 := b3;; ####### \tau_3^- is an algebra homomorphism ##### rel0(tau3mb1,tau3mb3); rel1(tau3mb1,tau3mb2); rel1(tau3mb2,tau3mb1); rel12(tau3mb3,tau3mb2); rel2(tau3mb3,tau3mb2); ####### \tau_3^- is the inverse of \tau_3 ########## tau3b3 * tau3b2 - _q^2 * tau3b2 * tau3b3 - b2; tau3mb2 * tau3mb3 - _q^2 * tau3mb3 * tau3mb2 -b2; ################################################################## ######## Verifying the braid relations ########################### ######## We write t2323 for tau_2 tau_3 tau_2(b3) etc. ########### ################################################################## t11:= b1;; t12:= b2*b1 - _q *b1*b2;; t13:= b3;; t21:= b1*b2-_q * b2*b1;; t22:= b2;; t23:= 2q^-1*b3*b2^2 -_q*b2*b3*b2+_q^2*2q^-1*b2^2*b3 + b3;; t31:= b1;; t32:= b2 * b3 - _q^2 * b3 * b2;; t33:= b3;; ############ t311:= b1;; t312:= t32*t31 - _q *t31*t32;; t313:= b3;; t131:= b1;; t132:= t12 * t13 - _q^2 * t13 * t12;; t133:= b3;; ############ t121:= t11*t12-_q * t12*t11;; t122:= t12;; t123:= 2q^-1*t13*t12^2 -_q*t12*t13*t12+_q^2*2q^-1*t12^2*t13 + t13;; ## t211:= t21;; t212:= t22*t21 - _q *t21*t22;; t213:= t23;; ## t231:=t21;; t232:= t22 * t23 - _q^2 * t23 * t22;; t233:=t23;; ## t321:=t31*t32-_q * t32*t31;; t322:=t32;; t323:=2q^-1*t33*t32^2 -_q*t32*t33*t32+_q^2*2q^-1*t32^2*t33 + t33;; ############ t2121:= t211*t212-_q * t212*t211;; t2122:= t212;; t2123:= 2q^-1*t213*t212^2 -_q*t212*t213*t212+_q^2*2q^-1*t212^2*t213 + t213;; ## t1211:= t121;; t1212:= t122*t121 - _q *t121*t122;; t1213:= t123;; ## t3231:=t321;; t3232:=t322 * t323 - _q^2 * t323 * t322;; t3233:=t323;; ## t2321:=t231*t232-_q * t232*t231;; t2322:=t232;; t2323:=2q^-1*t233*t232^2 -_q*t232*t233*t232+_q^2*2q^-1*t232^2*t233 + t233;; ############ t23231:=t2321;; t23232:=t2322 * t2323 - _q^2 * t2323 * t2322;; t23233:=t2323;; ## t32321:=t3231*t3232-_q * t3232*t3231;; t32322:=t3232;; t32323:=2q^-1*t3233*t3232^2 -_q*t3232*t3233*t3232+_q^2*2q^-1*t3232^2*t3233 + t3233;; ######## braid relations ################################# t132-t312; t2121-t1211; t2122-t1212; t2123-t1213; t32321-t23231; t32322-t23232; t32323-t23233; ######## :-) End :-) #####################################