منابع مشابه
Associativity and Non-Associativity of Some Hypergraph Products
Several variants of hypergraph products have been introduced as generalizations of the strong and direct products of graphs. Here we show that only some of them are associative. In addition to the Cartesian product, these are the minimal rank preserving direct product, and the normal product. Counter-examples are given for the strong product as well as the non-rank-preserving and the maximal ra...
متن کاملTheorem Proving modulo Associativity
We present an inference system for rst-order constrained clauses with equality modulo associativity (A). Our procedure is refutationally complete and reduces to Knuth-Bendix completion modulo A in the equational case. As an essential ingredient we present the rst |as far as we know| A-compatible reduction ordering total on the ground A-congruence classes.
متن کاملPartial monoids: associativity and confluence
A partial monoid P is a set with a partial multiplication × (and total identity 1P ) which satisfies some associativity axiom. The partial monoid P may be embedded in the free monoid P ∗ and the product × is simulated by a string rewriting system on P ∗ that consists in evaluating the concatenation of two letters as a product in P , when it is defined, and a letter 1P as the empty word ǫ. In th...
متن کاملAssociativity as commutativity
It is shown that coherence conditions for monoidal categories concerning associativity are analogous to coherence conditions for symmetric or braided strictly monoidal categories, where associativity arrows are identities. Mac Lane’s pentagonal coherence condition for associativity is decomposed into conditions concerning commutativity, among which we have a condition analogous to naturality an...
متن کاملInfinite unfair shuffles and associativity
We consider a general shuffling operation for finite and infinite words which is not necessarily fair. This means that it may be the case that in a shuffle of two words, from some point onwards, one of these words prevails ad infinitum even though the other word still has letters to contribute. Prefixes and limits of shuffles are investigated, leading to a characterization of general shuffles i...
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: Letters in Mathematical Physics
سال: 2008
ISSN: 0377-9017,1573-0530
DOI: 10.1007/s11005-008-0266-3