A hierarchy of primitive recursive sequence functions
We study iteration and recursion operators in the denotational semantics of typed λ-calculi derived from the multiset relational model of linear logic. Although these operators are defined as fixpoints of typed functionals, we prove them finitary in the sense of Ehrhard’s finiteness spaces.
In this paper the computational complexity of the problem of the approximation of a given dissimilarity measure on a finite set by a -ultrametric on and by a Robinson dissimilarity measure on is investigared. It is shown that the underlying decision problems are NP-complete.