anchor.diff:    mkNotdef = {_type = "notdef";};
   
     # General property type, it has a property attribute and a content
  -  # attribute.  The property attribute refer to an attribute set which
  +  # attribute.  The property attribute refers to an attribute set which
     # contains a _type attribute and a list of functions which are used to
  -  # evaluate this property.  The content attribute is used to stack property
  +  # evaluate this property.  The content attribute is used to stack properties
     # on top of each other.
     # 
     # The optional functions which may be contained in the property attribute
  
positive.code:     else
        p;
  
    # Ignore all values which have a higher value of the priority number.
    onOverrideGlobalEval = valList:
      let
        defaultPrio = 100;
  
negative.code:   /* mkOverride */
  
    # Create an "Override" statement which allow the user to define
    # priorities between values.  The default priority is 100. The lowest
    # priorities are kept.  The template argument must reproduce the same
    # attribute set hierarchy to override leaves of the hierarchy.
    isOverride = attrs: (typeOf attrs) == "override";
    mkOverride = priority: template: content: mkProperty {
      property = {
  