human isa thingwhere human and thing are concepts, and person and man are words; isa and words are the only two keywords. This file indicates that human is a subtype of thing, and human is associated with the words person and man. Concept names should begin with a lower-case letter, and may contain lower and upper case letters; a word is normally all lower case. No two concepts in the hierarchy can have the same name, and no two words in the hierarchy can be the same. A concept name and a word can be the same though.
human words person, man
Concept hierarchy files should typically have the file extension .hrc.
Concepts.fileName = filenamein the Jet properties file.
feature ?isa(concept)This feature test succeeds if the value of feature is a word associated with concept, or associated with some concept' which is a descendant of concept in the hierarchy.
The Concept Hierarchy UI is an editor for concept hierarchy (.hrc) files. You start the Concept Hierarchy UI by selecting "Concept Window" in the Jet File menu. If a hierarchy has been specified in the Jet properties file, it will appear
The Concept Hierarchy UI has the basic features of an editor such as those for a text editor.
File Open, Save, SaveAs and Exit do the standard file IO (note that Exit quits Jet, not just the UI). If a concept hierarchy file is changed after it was last saved, it is marked as dirty with an asterisk after the file name in the window caption. A dialog message will pop up asking if the current file is to be saved. There is a bug here: if the window is being closed when the file is dirty, a dialog pops up, and then the "cancel" button is pressed, the window will become invisible without anything done to the file. If the "Exit" menu item is chosen instead, everything works just as fine.
From the "Edit" menu, you can add, delete, rename and search concepts and words. There is a bug here: when you rename a concept or word either by selecting the "Rename" menu item or clicking on the concept or word itself, then type in the new name and carriage return, an error message will pop out if the new name is an empty string or causes duplicate in the hierarchy. After you press OK to get rid of the message, the concept or word is still being edited, if you press ESC, the bad name will be accepted. It's the user's responsibility not to deliberately introduce this kind of error into the file at the time being because the editor is not so stubborn as to give the same advice twice.
The Drag-and-Drop feature has been added to the editor, making it easier
to move a large portion of a hierarchy from one place to another. Note
that only move is provided but not copy, even though by pressing CTRL when
dragging a node, the cursor will have a "+" sign. The copy function is
not provided because no duplicate concepts and words are allowed in a hierarchy.