Set up a multivariate model formula for use in the brms package
allowing to define (potentially non-linear) additive multilevel
models for all parameters of the assumed response distributions.

`mvbrmsformula(..., flist = NULL, rescor = NULL)`

## Arguments

- ...
Objects of class `formula`

or `brmsformula`

,
each specifying a univariate model. See `brmsformula`

for details on how to specify univariate models.

- flist
Optional list of formulas, which are treated in the
same way as formulas passed via the `...`

argument.

- rescor
Logical; Indicates if residual correlation between
the response variables should be modeled. Currently, this is only
possible in multivariate `gaussian`

and `student`

models.
If `NULL`

(the default), `rescor`

is internally set to
`TRUE`

when possible.

## Value

An object of class `mvbrmsformula`

, which
is essentially a `list`

containing all model formulas
as well as some additional information for multivariate models.

## Examples

```
bf1 <- bf(y1 ~ x + (1|g))
bf2 <- bf(y2 ~ s(z))
mvbf(bf1, bf2)
#> y1 ~ x + (1 | g)
#> y2 ~ s(z)
```