How Core Erlang handles nested function application

test.core

module 'test' ['f'/0,
	       'module_info'/0,
	       'module_info'/1,
	       'three'/0]
    attributes []
'f'/0 =
    %% Line 5
    fun () ->
	%% Line 6
	( fun (_cor2) ->
	      %% Line 7
	      ( fun (_cor0) ->
		    %% Line 8
		    call 'erlang':'+'
			(_cor2, _cor0)
		-| [{'id',{0,0,'-f/0-fun-0-'}}] )
	  -| [{'id',{0,0,'-f/0-fun-1-'}}] )
'three'/0 =
    %% Line 13
    fun () ->
	let <_cor0> =
	    %% Line 14
	    apply 'f'/0
		()
	in  let <_cor1> =
		%% Line 14
		apply _cor0
		    (1)
	    in  let <_cor2> =
		    %% Line 14
		    apply _cor1
			(2)
		in  let <_cor3> =
			%% Line 14
			apply 'f'/0
			    ()
		    in  let <_cor4> =
			    %% Line 14
			    apply _cor3
				(0)
			in  let <_cor5> =
				%% Line 14
				apply _cor4
				    (3)
			    in  %% Line 14
				[_cor2|[_cor5|[]]]
'module_info'/0 =
    ( fun () ->
	  ( call ( 'erlang'
		   -| ['compiler_generated'] ):( 'get_module_info'
						 -| ['compiler_generated'] )
		(( 'test'
		   -| ['compiler_generated'] ))
	    -| ['compiler_generated'] )
      -| ['compiler_generated'] )
'module_info'/1 =
    ( fun (( _cor0
	     -| ['compiler_generated'] )) ->
	  ( call ( 'erlang'
		   -| ['compiler_generated'] ):( 'get_module_info'
						 -| ['compiler_generated'] )
		(( 'test'
		   -| ['compiler_generated'] ), ( _cor0
						  -| ['compiler_generated'] ))
	    -| ['compiler_generated'] )
      -| ['compiler_generated'] )
end

test.erl

-module(test).

-export([f/0, three/0]).

f() ->
    fun (X) ->
            fun (Y) ->
                    X + Y
            end
    end.


three() ->
    [((f())(1))(2), ((f())(0))(3)].