flex Expert System Toolkit - LPIS

7. Knowledge Specification Language 83
Instances
flex toolkit
is a kind of.
Examples
frame macintosh is a kind of computer .
frame green_picture is a picture ;
default colour is green .
To specify inheritance of particular attributes, use the keywords
inherit ... from
do not inherit.
Examples
frame wedge is a kind of block , toy ;
do not inherit shape and
inherit volume from block and
inherit density from pyramid, toy .
frame block
default volume is its size to the power of 3 and
default shape is regular ;
inherit usage from toy .
An instance is a particular instance of a frame, differing from the frame
itself in that an instance can have only one parent frame, can have no
children, and all its values are deemed to be current values (so it may not
have default values declared).
Instances may have inheritance declared as for frames.
For instances, use the KSL format
instance Instance is a Frame ;
Attribute is Value .
or
instance Instance is an Frame
instance Instance is a kind of Frame
instance Instance is an instance of Frame
Examples
instance brick7 is an instance of brick ;
shape is cuboid .
instance tweety_pie is a kind of bird ;
habitat is a cage and
predator is tom ;
do not inherit motions .
instance smudge is a cat ;
meal is rabbit .