# Prior for parameters which are not described in model block

If I write the following in stan file, then what priors are used by rstan::stan() ? In model block I do not write any distributions for parameters m,v.
I think for parameter m the constant function is used.
I think for parameter v the constant function which is one on the interval [o,\infty] and 0 on otherwise.

Or is it used the inverse gamma? I am not sure what priors are used?

parameters{

real m;
real <lower=0>v;

}

• Operating System: Win 10
• brms Version:

Constant over the ranges specified in the parameters block.

Thank you !!

Please let me know the following.
Suppose that

parameters{

real <lower= 0, upper= 1 > v;

}


Then, which does the support of the uniform prior of v correspond the following:

1. closed interval [0,1]
2. open interval (0,1)

Closed, but it doesn’t matter

i appreciate for rapid reply. I think “it doesn’t matter” means that the value in the endpoints of the interval never be chosen in numerical process. But I want to write some paper, so theoretically, I want to know it !! Thank you !!