###

    # KEHOME/knowledge/theory/KRdesign/keyidea.html
    # Jul/16/2002
    # new syntax Sep/3/2002

    #=======================================#
    # key ideas of knowledge representation #
    #=======================================#

    # existence
    	entity isa existent
    # identity
    	entity has attribute = value
    	entity do action = event od aobject done
    	entity isin relation = infon
    # consciousness
    	I do perceive od entity done

    # knowledge
    	knowledge := I do identify od existent done
    # knowledge unit (knit)
    	knit isa knowledge
    	knit has view=v
    	at view=v				# context
    	knit := I do identify od existent done	# concept-hierarchy

    # change
    	event changes eobject \
    		from attribute=initial \
    		to attribute=final
    # change unit (chit)
    	knit haspart chit
    	chit has space=s,time=t,view=v
    	at space=s, time=t, view=v	# context
    	entity do action = event od aobject done
    	event changes eobject \
    		from attribute=initial \
    		to attribute=final

    # definition by differentiation (genus-differentia)
    	concept is genus with essential-characteristic
    # definition by integration (ostensive)
    	concept is either unit:1 or unit:2 or ...
    # definition by identity
    	concept:1 is concept:2

    # relation
    	relation is existent with
    		format=[class:1; ...; class:n],
    		meaning={... $1 ... $n ...}
    # causality (phenomenon)
    	event:1 causes event:2
    # part
    	entity haspart part=partcount

    # concept-formation by integration
    	concept isi unit:1,unit:2,... with
    		common-characteristic
    # concept-formation by differentiation
    	concept:1,concept:2,... isd genus with
    		distinguishing-characteristic
    # meaning
    	symbol means referent

    # sentence
    	sentence isa knit
    	sentence ise statement,command,question,assignment
    # conditional
    	if sentence:1 then sentence:2 else sentence:3 fi
    # iteration (use $variable within sentence)
    	every variable isa concept { sentence }
    # method
    	method is action with
    		format=[class:1; ...; class:n],
    		meaning={... $1 ... $n ...}

    # statement
    	subject verb object pplist

    # command
    	do action od aobject pplist done
    	do method od aobject pplist done
    	vdo find od name done	# all views

    # question
    	subject verb object ?	# true or false
    	subject verb ?		# matching objects
    	subject ? object	# relation between subject and object
    	? verb object		# matching subjects

    # assignment
    	set variable = value

    # characteristic and part
    	hchar is begin hierarchy
    	existent
    	/    characteristic
    	//	attribute
    	///	    space
    	///	    time
    	///	    view
    	//	action
    	//	relation
    	//      part
    	end hierarchy hchar

General References