dynare代码运行报错，求大神解答

var y c n k i mc w r rk a;
varexo etaa;
parameters beta sigma varphi Omega epsilon alpha delta mu rho sigmaa rss rkss Theta;
beta=0.99;
sigma=2.10;
varphi=1.99;
Omega=1.20;
epsilon=4.61;
alpha=0.4;
delta=0.025;
mu=(epsilon-1)/epsilon;
rho=0.88;
sigmaa=0.01;
rss=1/beta;
rkss=rss+delta;
Theta=alpha*mu/(rkss-1);

model(linear);
sigma * (c(+1) - c)= r;
varphi * n + sigma * c = w;
rkss * rk(+1) = rss*r;
k(-1) + rkss/(rkss - 1)*rk = mc + y;
w + n = mc + y;
mc = 0;
y = a + alpha * k(-1) + (1-alpha) * n;
y = (1-delta*Theta)*c+delta*Theta*i;
k = (1-delta) * k(-1) + delta * i;
a = rho * a(-1) + etaa;
end;

initval;
r = 0;
w = 0;
a = 0;
mc = 0;
y = 0;
c = 0;
n = 0;
k = 0;
i = 0;
rk = 0;
end;

steady;
check;

shocks;
var etaa=sigmaa^2;
end;
stoch_simul(irf=40,order=1,periods=20000,drop=400);

报错：ERROR: capital.mod: line 35, col 1 - line 36, col 4: r is not a parameter