```
data {
int<lower=0> N;
int<lower=0> K;
matrix[N,K] y;
matrix[N,K] X;
}
parameters {
matrix[K,K] lambda_hat;
matrix[K,K] sigma_0;
matrix[K,K] L;
}
transformed parameters {
matrix[N,K] mu;
vector[4] v;
for (i in 1:K)
v[i]=1;
for (i in 1:N)
mu[i,]'=lambda_hat*x[i,]';
}
model {
L~ wishart(K,diag_matrix(v));
sigma_0~ wishart(K,L);
lambda_hat~ wishart(K,L);
for (t in 1:N)
y[t,]'~ multi_normal(y[(t-1),]'+mu[t,]',sigma_0);
}
```

I am having the following error when I run this code,

```
rt = stanc("mystancode.stan")
```

```
SYNTAX ERROR, MESSAGE(S) FROM PARSER:
Illegal statement beginning with non-void expression parsed as
transpose(mu[i, :])
Not a legal assignment, sampling, or function statement. Note that
* Assignment statements only allow variables (with optional indexes) on the left;
* Sampling statements allow arbitrary value-denoting expressions on the left.
* Functions used as statements must be declared to have void returns
error in 'model2e850c17b4_mystancode' at line 20, column 7
-------------------------------------------------
18:
19: for (i in 1:N)
20: mu[i,]'=lambda_hat*x[i,]';
^
21:
-------------------------------------------------
PARSER EXPECTED: <statement>
Error in stanc("mystancode.stan") :
failed to parse Stan model 'mystancode' due to the above error.
```

Please help me out.