Results 51 to 60 of about 53,013 (201)
Congruence Closure Modulo Groups [PDF]
Logical Methods in Computer ScienceThis paper presents a new framework for constructing congruence closure of a finite set of ground equations over uninterpreted symbols and interpreted symbols for the group axioms.
Dohan Kim
doaj +1 more source
Mixed Steiner Triple Systems With Shortest Length
Journal of Combinatorial Designs, EarlyView.ABSTRACT A mixed Steiner triple system is a 3‐GDD which is viewed as a code with minimum Hamming distance 3. These codes are the minimum weight codewords of a 1‐perfect code over a mixed alphabet, when the related codes exist, and provide the connection between 3‐GDDs and coding theory.
Tuvi Etzion
wiley +1 more source
Checking Zenon Modulo Proofs in Dedukti
, 2015 International audienceDedukti has been proposed as a universal proof checker. It is a logical framework based on the λΠ-calculus modulo that is used as a backend to verify proofs coming from theorem provers, especially those implementing some form of ...
Cauderlier, Raphaël, Halmagrand, Pierre
core +2 more sources
On Odd Covers of Cliques and Disjoint Unions
Journal of Graph Theory, EarlyView.ABSTRACT Babai and Frankl posed the “odd cover problem” of finding the minimum cardinality of a collection of complete bipartite graphs such that every edge of the complete graph of order n $n$ is covered an odd number of times. In a previous paper with O'Neill, some of the authors proved that this value is always ⌈ n / 2 ⌉ $\lceil n/2\rceil $ or ⌈ n /
Calum Buchanan +7 more
wiley +1 more source
Efficiently Simulating Higher-Order Arithmetic by a First-Order Theory Modulo [PDF]
Logical Methods in Computer Science, 2011 In deduction modulo, a theory is not represented by a set of axioms but by a congruence on propositions modulo which the inference rules of standard deductive systems---such as for instance natural deduction---are applied.
Guillaume Burel
doaj +1 more source
Congruences modulo $4$ for the number of $3$-regular partitions
Comptes Rendus. Mathématique, 2023 The last decade has seen an abundance of congruences for $b_\ell (n)$, the number of $\ell $-regular partitions of $n$. Notably absent are congruences modulo $4$ for $b_3(n)$. In this paper, we introduce Ramanujan type congruences modulo $4$ for $b_3(2n)$
Ballantine, Cristina, Merca, Mircea
doaj +1 more source
Explicit 3‐colorings for Exponential Graphs
Journal of Graph Theory, EarlyView.ABSTRACT In 1985, El‐Zahar and Sauer showed that the chromatic number of the direct product of two 4‐chromatic graphs is 4, establishing a nontrivial case of Hedetniemi's conjecture, which has since been refuted in general. Their proof uses the concept of an exponential graph, showing that if a graph H $H$ has no proper 3‐coloring, then the exponential
Adrien Argento +2 more
wiley +1 more source
Line Graphs of Multigraphs and the Forbidden Graph E 6
Journal of Graph Theory, EarlyView.ABSTRACT The line graph Γ of a multigraph Δ is the graph whose vertices are the edges of Δ, where two such edges are adjacent if and only if they meet in a single vertex of Δ. We provide several characterizations of such line graphs and in particular show that a graph is a line graph if and only if it does not contain one of the 32 graphs, all of which
Hans Cuypers
wiley +1 more source
Obstructions for Homomorphisms to Odd Cycles in Series‐Parallel Graphs
Journal of Graph Theory, EarlyView.ABSTRACT For a graph H $H$, an H $H$‐colouring of a graph G $G$ is a vertex mapping ϕ : V ( G ) → V ( H ) $\phi :V(G)\to V(H)$ such that adjacent vertices are mapped to adjacent vertices. A graph G $G$ is C 2 k + 1 ${C}_{2k+1}$‐critical if G $G$ has no C 2 k + 1 ${C}_{2k+1}$‐colouring but every proper subgraph of G $G$ has a C 2 k + 1 ${C}_{2k+1 ...
Eun‐Kyung Cho +3 more
wiley +1 more source
Characterization of Graphs Without Even F $F$‐Orientations
Journal of Graph Theory, EarlyView.ABSTRACT A graph G $G$ is 1‐extendable if every edge belongs to at least one 1‐factor of G $G$. Let G $G$ be a graph with a 1‐factor F $F$. Then an even (odd) F $F$ ‐orientation of G $G$ is an orientation in which each F $F$‐alternating cycle has exactly an even (odd) number of edges directed in the same fixed direction around the cycle.
Marién Abreu +3 more
wiley +1 more source