The main result of the paper is a constructive proof of the following equivalence: two pure -terms are observationally equivalent in the lazy concurrent -calculus i they have the same L evy-Longo trees. An algorithmwhich allows to build a context discriminating any two pure -terms with di erent L evy-Longo trees is described. It follows that contextual equivalence coincides with behavioural equ...

Abstract : Let be a 2nd order ODE. By Cartan equivalence method, we will study the local equivalence problem under the transformations group of time-fixed coordinates. We are going to solve this problem by an applicable method which has been recognized by R. Gardner, and classify them.   

in welfare economic studies, because of the differences among households scale, we cannot consider household expenditures without attention to this factor. a simple method to consider household scale in welfare analysis is the usage of the per capita expenditure. but, the usage of per capita expenditure ignores economies of scale. in fact, per capita expenditure is a biased variable, and underv...

in this paper we enumerate fuzzy subgroups, up to a natural equivalence, of some finite abelian p-groups of rank two where p is any prime number. after obtaining the number of maximal chains of subgroups, we count fuzzy subgroups using inductive arguments. the number of such fuzzy subgroups forms a polynomial in p with pleasing combinatorial coefficients. by exploiting the order, we label the s...

in this paper we classify fuzzy subgroups of a rank-3 abelian group $g = mathbb{z}_{p^n} + mathbb{z}_p + mathbb{z}_p$ for any fixed prime $p$ and any positive integer $n$, using a natural equivalence relation given in cite{mur:01}. we present and prove explicit polynomial formulae for the number of (i) subgroups, (ii) maximal chains of subgroups, (iii) distinct fuzzy subgroups, (iv) non-isomorp...

Kripke Structures and Labelled Transition Systems are the two most prominent semantic models used in concurrency theory. Both models are commonly believed to be equi-expressive. One can find many ad-hoc embeddings of one of these models into the other. We build upon the seminal work of De Nicola and Vaandrager that firmly established the correspondence between stuttering equivalence in Kripke S...