A '''differential propositional calculus''' is a [[propositional calculus]] extended by a set of terms for describing processes that take place in a [[universe of discourse]] or transformations that map a source universe into a target universe.
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A '''differential propositional calculus''' is a [[propositional calculus]] extended by a set of terms for describing aspects of change and difference, for example, processes that take place in a [[universe of discourse]] or transformations that map a source universe into a target universe.