MATLAB 7.0 display an error message

MATLAB Program：

syms x y z b c Y

a1 = 1;

a2 = 1;

e1 = 9;

e2 = 7;

f1 = 56

f2 =98;

g1 = 76;

g2 = 665;

% a = a1+a2;

% e = e1+e2; % f = f1+f2; % g = g1+g2;

e = 1;

f = 1;

g = 1;

a = 1;

%

solve(diff(x) == z-y+b*c-c*y-y^2-c*y-c-e-f-g,...

    diff(y)==x-z+b*z-y^2-c^2-c*y-e*f-g,...

    diff(z) == y-x+c*x-b*z+z+b+e*g+f,...

    0==b*c+y*z+e*f+e*g-Y,...

    diff(b) == a*c+x*z+z+e*f*g*Y,...

    diff(c) == a*b+x*y-e*f*x-y^2*c-y*c^2-e*f-f*g,...

    x, y , z ,b ,c, Y)

Do you think the Matlab program is correct? Someone is insisting it is right.

Could solutions be obtained by using the solve()function？