p = defn bistable_oscillator

$Xo -> So;  k0*Xo;
So -> S1;   k1*So + Vmax*So*S1^n/(15 + S1^n);
S1 -> $X1;  k2*S1;

end;

p.Xo = 1;
p.X1 = 0;
p.S1 = 1;
p.n = 4;
p.Vmax = 12;
p.k0 = 0.044;
p.k1 = 0.01;
p.k2 = 0.1;