maximalSorts and minimalSorts

The operations maximalSorts and minimalSorts take as arguments the metarepresentation of a module $\mathcal{R}$ and the metarepresentation of a kind $k$. If $k$ is a kind in $\mathcal{R}$, maximalSorts returns the metarepresentation of the set of the maximal sorts in the connected component of $k$, while minimalSorts returns the metarepresentation of the set of its minimal sorts.

  op maximalSorts : Module Kind ~> SortSet [special (...)] .
  op minimalSorts : Module Kind ~> SortSet [special (...)] .

For example,

  Maude> reduce in META-LEVEL :
     maximalSorts(upModule('NUMBERS, false), '`[Zero`]) .
  result NeSortSet: 'NatSeq ; 'NatSet

  Maude> reduce in META-LEVEL :
     minimalSorts(upModule('NUMBERS, false), '`[Zero`]) .
  result NeSortSet: 'Zero ; 'NzNat