Question: System of parametric equations

Hello,

I'm quite new to Maple and I have a serious problem when I'm trying to solve this system of equations for (a,b,p,v,u,g):

1) alpha[1]= v a u (1- b)
2) alpha[2]= v a ub
3) alpha[3]= v (1-a)=v-va
4) alpha[11]= 1/(2) auv (-1+b) (-b u p+b a u p+b g+p u-u p a) 
5) alpha[22]= 1/(2) a u v b (-b u p+b a u p+b g-g)
6) alpha[33]= 1/(2)(a- 1)apv
7) alpha[12]= -a u v b(pu-pua-g - bup +baup +bg)
8) alpha[13]= (a-1) (b-1)ap vu
9) alpha[23]= (1-a) a p v ub

I tried this command:

solve({v*(1-a) = alpha[3], a*u*v*b = alpha[2], v*a*u*(1-b) = alpha[1], (1/2*(-1+a))*a*p*v = alpha[33], (-1+a)*(-1+b)*a*p*v*u = alpha[13], (1-a)*a*p*v*u*b = alpha[23], (1/2)*a*u*v*b*(-b*u*p+b*a*u*p+b*g-g) = alpha[22], -a*u*v*b*(p*u-u*p*a-g-b*u*p+b*a*u*p+b*g) = alpha[12], (1/2)*a*u*v*(-1+b)*(-b*u*p+b*a*u*p+b*g+p*u-u*p*a) = alpha[11]}, {a, b, g, p, u, v}, 'parametric' = 'full', 'parameters' = {alpha[1], alpha[2], alpha[3], alpha[11], alpha[12], alpha[13], alpha[22], alpha[23], alpha[33]})

 but the Maple output is [ ]. I can find a solution manually but I don't understand why I cannot do it with Maple. It's very important that I find a solution as I have a much more complicated system to solve in a similar manner.

Thank you very much for your help!!

Elena