completion does not work for functions starting with "$"

[behrica]

incanter, for example, contains some functions starting with a "$",
like '$rollup'.

The completion of those names does not work.

(ns zealous-atoll
  (:require [gorilla-plot.core :as plot]
            [incanter.core :as ic]
         
  ))

Pressing control-tab after 'ic/' shows correctly the list of all functions.
But pressing it after "ic/$r" does not work.

Neither does it work to get the function documentation by pressing control-tab after "ic/$rollup'