URL_Value : sub_class_of : String_Value

This item represents a particular type of constant value that can be used as the object of connections. For example, in the statement "SallySinger webSiteIs 'http://sally-stringer.tld/'", the "http..." string is a Web Address-type constant value. The system checks the address (URL) supplied for syntax, but does not currently test that the location referenced actually exists. In addition to the web address itself, a URL_Value-constant can contain additional text, separated from the web address by spaces. (Note that URLs are not allowed to contain spaces, so there is no opportunity for confusion.) When creating pages that use a URL_Value to create links, if additional text is present in the URL_Value, it will be used for the text of the link instead of the actual web address.

This relationship is used to connect two items, both representing classes, indicating that the subject item is a sub-class of the object item. For example, the connection "Ships is a SubClass-Of Vehicles" links the two class items, and makes the statement that "Ships" are a more specific kind of "Vehicles". Once this connection is established, the system will behave as if everything that is true about "Vehicles" is also true for "Ships" (although not vice-versa). For example, if another property is defined such that its object items are required to be instances of the "Vehicles" class, then having this connection allows instances of "Ships" to be used as well. But, another property whose objects are required to be "Ships" is not affected, and other "Vehicles" still cannot be used.

This item represents a particular type of constant value that can be used as the object of connections. For example, in the statement "SallySinger sFavoriteColorIs 'Blue'", "Blue" is a String-type constant value. The system doesn't perform any checks on the content of String constant aside from ensuring that they are not empty and not too long.