Programming Language Theory: Difference between revisions
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** Subsumption properties can't be arbitrarily enforced (decided) when subclasses override the implementation | ** Subsumption properties can't be arbitrarily enforced (decided) when subclasses override the implementation | ||
** ''Soundness'' refers to data structuring operation support for subtyping, such as annotation of type alterations: | ** ''Soundness'' refers to data structuring operation support for subtyping, such as annotation of type alterations: | ||
*** | *** ''Covariant'' modifications retain the original ordering | ||
*** | *** ''Contravariant'' modifications invert the original ordering | ||
*** | *** ''Invariant'' modifications dissolve the subsumption relation | ||
* Support for ''minimal'' and ''maximal'' types (also known as Bottom and Top) | * Support for ''minimal'' and ''maximal'' types (also known as Bottom and Top) | ||
===Conversion=== | ===Conversion=== | ||