We show that the category of algebraically cofibrant objects in a combinatorial and simplicial model category A has a model structure that is left-induced from that on A. In particular it follows that any presentable model category is Quillen equivalent (via a single Quillen equivalence) to one in which all objects are cofibrant. Let A be a cofibrantly generated model category. Garner’s version...

We sketch the process of creating a novel video game by blending two video games specified in the Video Game Description Language (VGDL), following the COINVENT computational model of conceptual blending. We highlight the choices that need to be made in this process, and discuss the prospects for a computational game designer based on blending. Introduction This paper outlines the process of cr...

For a small category K enriched over a suitable monoidal category V , the free completion of K under colimits is the presheaf category [K ,V ]. If K is large, its free completion under colimits is the V -category PK of small presheaves on K , where a presheaf is small if it is a left Kan extension of some presheaf with small domain. We study the existence of limits and of monoidal closed struct...

A rich concurrent semantics has been developed along the years for graph transformation systems, often generalizing in non-trivial ways concepts and results first introduced for Petri nets. Besides the theoretical elegance, the concurrent semantics has potential applications in verification and model checking, as witnessed by techniques like partial order reduction or the use of finite, complet...

Among the list of proposed questions in “Open Problems in Artificial Life” (Bedau et al. 2000) the first, “how does life arise from the nonliving?” is certainly one of the most difficult to answer. The first and main challenge in the understanding of the way that life emerged from the nonliving comes from our lack of knowledge of the living organism and paradoxically, the limitations which we i...

Call a category "sketchable" if it is the category of models in sets of some sketch. This paper explores the subtle boundary between sketchable and nonsketchable categories. We show that the category of small categories that have at least one initial object and functors that take an initial object to an initial object is sketchable. The same is true for weak initial objects, but is false for su...

This paper begins the discussion of how the Information Flow Framework can be used to provide a principled foundation for the metalevel (or structural level) of the Standard Upper Ontology (SUO). This SUO structural level can be used as a logical framework for manipulating collections of ontologies in the object level of the SUO or other middle level or domain ontologies. From the Information F...

We have discovered that coastal and oceanic diatoms require more manganese (Mn) to grow in iron (Fe) -deficient than in Fe-sufficient seawater. At low inorganic concentrations, like those of the open sea, Fe and Mn can thus colimit Thalassiosira pseudonana and T. oceanica so that maximum rates of cell division are achieved only when both resources are added simultaneously to cultures. Colimited...

namely 90 a M0 a M! a M1 a Yset : set !Mset: We recall from [8] or [9] that a locally small category B is said to be total (abbreviating totally cocomplete) if Y : B !MB has a left adjoint, X: Considerable motivation for the terminology is given in either reference. Examples include categories of algebras, categories of spaces and categories of sheaves on a Grothendieck site. The reader is advi...

Let G be a group of automorphisms of a category C. We give a definition for a functor F : C → C to be a G-covering and three constructions of the orbit category C/G, which generalizes the notion of a Galois covering of locally finitedimensional categories with group G whose action on C is free and locally bonded. Here C/G is defined for any category C and we do not require that the action of G ...