sts of the
| qualities or properties which go to make up the
| concept.  The 'extension' of a concept consists
| of the things which fall under the concept;  or,
| according to another definition, the 'extension'
| of a concept consists of the concepts which are
| subsumed under it (determine subclasses).  This is
| the old distinction between intension and extension,
| and coincides approximately with the distinction between
| a monadic 'propositional function' (q.v.) in intension and
| a 'class' (q.v.).  