anchor.diff:           reduce_sort/2,
            reduce_string_to_integer/2,
            reduce_sum/2,
  -         reduce_plist_sum/2]).
  +         reduce_plist_sum/2,
  +         reduce_count_inputs/2]).
   
   %-ifdef(TEST).
   -include_lib("eunit/include/eunit.hrl").
  
positive.code:     [1,2,3] = reduce_string_to_integer([<<"1">>, <<"2">>, <<"3">>], none),
      [1,2,3,4,5] = reduce_string_to_integer(["1", <<"2">>, <<"3">>, "4", "5"], none),
      [1,2,3,4,5] = reduce_string_to_integer(["1", <<"2">>, <<"3">>, 4, 5], none).
  
negative.code:          reduce_sort/1,
           reduce_string_to_integer/1,
           reduce_sum/1,
           reduce_plist_sum/1,
           reduce_count_inputs/1]).
  
  %% phase function definitions
  -export([map_identity/3,
  