anchor.diff:  with import ./lists.nix;
   with import ./attrsets.nix;
   with import ./options.nix;
  +with import ./trivial.nix;
   
   rec {
   
  
positive.code:       inherit name check merge iter fold docPath hasOptions delayOnGlobalEval;
      };
  
      
    types = rec {
  
      inferred = mkOptionType {
  
negative.code:     _type = typeName;
    };
  
  
    # name (name of the type)
    # check (boolean function)
    # merge (default merge function)
  