#
#
#

#
# 
#
#
data {
	int<lower=1> n;
	array[n] real x;
	array[n] real y;
}
parameters {
	real alpha;
	real <lower=0> sigma;
	real phi1;
	real phi2;
}
transformed parameters {
real<lower=0> v;
v=10*0.05/sigma^2;
}
model {
	alpha ~ normal(0,4);
	phi1 ~ normal(0,0.25);
	phi2 ~ normal(0,0.16);
	v ~ gamma(20,0.5);
	for (i in 3:n)
	y[i] ~ normal(alpha*x[i]+phi1*(y[i-1]-alpha*x[i-1])+phi2*(y[i-2]-alpha*x[i-2]),sigma);
}