# KEHOME/knowledge/ExamplesLogic/CategoricalStatement.txt
# July 27, 2002

#========================#
# categorical statements #
#                        #
# Richard H. McCullough  #
#========================#

# The standard categorical statement has the form
#
#	s S is p P
#
# where S is the "subject", P is the "predicate"
# and s,p are optional quantifiers chosen from
#
#	all
#	some
#	no
#	not

# The most widely used forms of categorical statements
# are type "A","E","I","O":
#
#	all  S is P	  # A
#	no   S is P	  # E
#	some S is P	  # I
#	some S is not P	  # O


#=========================================

# What are the meanings of "S", "P", "is"?

# In the most common case,
# S and P are sets of existents
# which have specific characteristics.
# For example,
#
#	man is mortal entity
#
# In this case, I will replace "is" by "isa*".
#
#	S isa* P
#
# which means that either
#
#	S is  P    (identity)
# or
#	S isa P    (subset)

# In the less common case,
# S is a set of existents
# and P is characteristics of the existents.
# For example,
#
#	man is mortal
#
# In this case, I will replace "is" by "has".
#
#	S has P