منابع مشابه
Finitely Stratified Polymorphism
We consider predicative type-abstraction disciplines based on type quantification with finitely stratified levels. The main technical result is that the functions representable in the finitely stratified polymorphic A-calculus are precisely the super-elementary functions, i.e. the class £4 in Grzegorczyk's subrecursive hierarchy. This implies that there is no super-elementary bound on the lengt...
متن کاملStratified polymorphism and primitive recursion
Natural restrictions on the syntax of the second order (i.e. polymorphic) lambda calculus are of interest for programming language theory. In [Leivant, 1991] one of the authors showed that when type abstraction in that calculus is stratified into levels, the definable numeric functions are precisely the super-elementary functions (level E4 in the Grzegorczyk Hierarchy). We define here a second ...
متن کاملThe polymorphism frequency spectrum of finitely many sites under selection.
The distribution of genetic polymorphisms in a population contains information about evolutionary processes. The Poisson random field (PRF) model uses the polymorphism frequency spectrum to infer the mutation rate and the strength of directional selection. The PRF model relies on an infinite-sites approximation that is reasonable for most eukaryotic populations, but that becomes problematic whe...
متن کاملSeparated finitely supported $Cb$-sets
The monoid $Cb$ of name substitutions and the notion of finitely supported $Cb$-sets introduced by Pitts as a generalization of nominal sets. A simple finitely supported $Cb$-set is a one point extension of a cyclic nominal set. The support map of a simple finitely supported $Cb$-set is an injective map. Also, for every two distinct elements of a simple finitely supported $Cb$-set, there exists...
متن کاملPresentations of Finitely Generated Submonoids of Finitely Generated Commutative Monoids
We give an algorithmic method for computing a presentation of any finitely generated submonoid of a finitely generated commutative monoid. We use this method also for calculating the intersection of two congruences on Np and for deciding whether or not a given finitely generated commutative monoid is t-torsion free and/or separative. The last section is devoted to the resolution of some simple ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Information and Computation
سال: 1991
ISSN: 0890-5401
DOI: 10.1016/0890-5401(91)90053-5