I’ve noticed that the `beta`

function in the math library isn’t currently exposed to the Stan language, and was adding signatures for it. But as Rok pointed out over on Github, `beta`

is a pretty common variable name and exposing it as a function could break current models.

At the moment, users can employ the beta function in stan models by specifying `exp(lbeta(a, b))`

, which is all the `beta`

function does in the math library anyway. So if it’s going be a userspace-breaking change, it might not be necessary to expose the function at all.

Alternatively, a simple fix could be to capitalise and denote it `Beta(a,b)`

, similar to the `Phi`

function.

Any thoughts/preferences here?