the notions of model
and theory into a (not necessarily sound) whole. It consists of a
component theory of types and a component model of instances that share
a common type language. The theory provides the formal semantics and
the model provides the interpretative semantics. A free prologic can be
constructed over any theory by adjoining to that theory the free model
of its base type language. The free passage from theories to prologics
and the component theory passage form the <span
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