anchor.diff:  -record(c_values, {anno=[], es}).	% es :: [Tree]
   
   -record(c_var, {anno=[], name :: cerl:var_name()}).
  -
  --record(c_map_pair, {anno=[],
  -	             op :: #c_literal{val::'assoc'} | #c_literal{val::'exact'},
  -		     key,
  -		     val}).
  -
  --record(c_map, {anno=[],
  -		arg=#c_literal{val=#{}} :: #c_var{} | #c_literal{},
  -		es :: [#c_map_pair{}]}).
  
positive.code: 
  -record(c_literal, {anno=[], val}).	% val :: literal()
  
  -record(c_module, {anno=[], name,	% name :: Tree,
  		   exports,		% exports :: [Tree],
  		   attrs,		% attrs :: [#c_def{}],
  
negative.code: -record(c_apply, {anno=[], op,		% op :: Tree,
  		  args}).		% args :: [Tree]
  
  -record(c_binary, {anno=[], segments :: [cerl:c_bitstr()]}).
  
  -record(c_bitstr, {anno=[], val,        % val :: Tree,
  		   size,		% size :: Tree,
  