# 1999/5/4

#=======#
# group #
#=======#

# A group is all of two or more similar units

  group is all unit1 and unit2 and ...

# Compare this to a concept.
# A concept is any one of two or more similar units

  concept is either unit1 or unit2 or ...

# Note that a "group" has a plural, collective nature,
# while a "concept" has a singular, individual nature.
# This is why I distinguish the two, even though they
# are both "mental integrations".

# Rand defines a concept as a mental integration of
# two or more units possessing the same distinguishing
# characteristics, with their particular measurements
# omitted.  Strictly speaking, that means that the
# "Rand concept" subsumes the "McCullough concept"
# and the "McCullough group".  However, I suspect Rand
# was thinking of the "McCullough concept" when she
# formulated her definition.  For example, see Rand,
# IOE, page 18.)


# The following abbreviated formats may be used:

  group isc unit1, unit2, ...
  unit1, unit2, ... ism group

# "isc" can be translated as "is a collection of".
# "ism" can be translated as "is a member of".


# By definition, the group and concept that subsume
# the same units are related by

  group is all concept
  concept is either group