Pattern completeness analysis
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This analysis analyzes an operation for a pattern-complete definition.
An operation is pattern complete if each pattern match is
defined for all constructors.
For instance, the operation
not True = False
not False = True
is pattern complete, whereas the operation
head (x:_) = x
is incomplete. If an operation is defined by overlapping rules,
it is complete if there is one alternative with complete pattern matching.
For instance, the operation
por True x = True
por x True = True
por False False = False
is not complete, since it corresponds to the following definition:
por x y = por1 x y ? por2 x y
por1 True _ = True
por1 False False = True
por2 _ True = True
Hence, each alternative is incomplete.