Can Elixir Kernel functions be traced by :dbg?

I’m new to Elixir and playing around with tracing. Following an example, I successfully setup :dbg to trace Enum.map/2 when executed inside iex. The trace event is created.

iex(3)> :dbg.tp(Enum, :map, [])   
{:ok, [{:matched, :nonode@nohost, 1}]}
iex(4)> :dbg.p(:all, :c)
{:ok, [{:matched, :nonode@nohost, 61}]}
iex(5)> Enum.map()
** (UndefinedFunctionError) function Enum.map/0 is undefined or private. Did you mean one of:

      * map/2

    (elixir 1.12.1) Enum.map()
(<0.109.0>) call 'Elixir.Enum':map([{1.0,map,2}],#Fun<Elixir.UndefinedFunctionError.7.56279482>)
iex(5)> 

I then tried to trace Kernel.rem/2 . This doesn’t appear to work. I tried a couple of other Kernel functions and they all didn’t produce a trace event.

iex(6)> :dbg.tp(Kernel, :rem, [])      
{:ok, [{:matched, :nonode@nohost, 1}]}
iex(7)> rem(1,1)
0
iex(8)> Kernel.rem(1,1)
0

Why are they not traced? Thank you