|
Action Language
In computer science, an action language is a language for specifying state transition systems, and is commonly used to create formal models of the effects of actions on the world. Action languages are commonly used in the artificial intelligence and robotics domains, where they describe how actions affect the states of systems over time, and may be used for automated planning. Action languages fall into two classes: action description languages and action query languages. Examples of the former include STRIPS, PDDL, Language A (a generalization of STRIPS; the propositional part of Pednault's ADL), Language B (an extension of A adding ''indirect effects'', distinguishing static and dynamic laws) and Language C (which adds indirect effects also, and does not assume that every fluent is automatically "inertial"). There are also the Action Query Languages P, Q and R. Several different algorithms exist for converting action languages, and in particular, action language C, to answ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to practical disciplines (including the design and implementation of hardware and software). Computer science is generally considered an area of academic research and distinct from computer programming. Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and for preventing security vulnerabilities. Computer graphics and computational geometry address the generation of images. Programming language theory considers different ways to describe computational processes, and database theory concerns the management of repositories ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satisfiability
In mathematical logic, a formula is ''satisfiable'' if it is true under some assignment of values to its variables. For example, the formula x+3=y is satisfiable because it is true when x=3 and y=6, while the formula x+1=x is not satisfiable over the integers. The dual concept to satisfiability is validity; a formula is ''valid'' if every assignment of values to its variables makes the formula true. For example, x+3=3+x is valid over the integers, but x+3=y is not. Formally, satisfiability is studied with respect to a fixed logic defining the syntax of allowed symbols, such as first-order logic, second-order logic or propositional logic. Rather than being syntactic, however, satisfiability is a semantic property because it relates to the ''meaning'' of the symbols, for example, the meaning of + in a formula such as x+1=x. Formally, we define an interpretation (or model) to be an assignment of values to the variables and an assignment of meaning to all other non-logical symbols, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automated Planning And Scheduling
Automation describes a wide range of technologies that reduce human intervention in processes, namely by predetermining decision criteria, subprocess relationships, and related actions, as well as embodying those predeterminations in machines. Automation has been achieved by various means including mechanical, hydraulic, pneumatic, electrical, electronic devices, and computers, usually in combination. Complicated systems, such as modern factories, airplanes, and ships typically use combinations of all of these techniques. The benefit of automation includes labor savings, reducing waste, savings in electricity costs, savings in material costs, and improvements to quality, accuracy, and precision. Automation includes the use of various equipment and control systems such as machinery, processes in factories, boilers, and heat-treating ovens, switching on telephone networks, steering, and stabilization of ships, aircraft, and other applications and vehicles with reduced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programming Language Classification
Program, programme, programmer, or programming may refer to: Business and management * Program management, the process of managing several related projects * Time management * Program, a part of planning Arts and entertainment Audio * Programming (music), generating music electronically * Radio programming, act of scheduling content for radio * Synthesizer programmer, a person who develops the instrumentation for a piece of music Video or television * Broadcast programming, scheduling content for television * Program music, a type of art music that attempts to render musically an extra-musical narrative * Synthesizer patch or program, a synthesizer setting stored in memory * "Program", an instrumental song by Linkin Park from ''LP Underground 11.0, LP Underground Eleven'' * Programmer, a film on the lower half of a double feature bill; see B-movie Science and technology * Computer program, a set of instructions that describes how to perform a specific task to a computer. * Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Event Calculus
The event calculus is a logical language for representing and reasoning about events and their effects first presented by Robert Kowalski and Marek Sergot in 1986. It was extended by Murray Shanahan and Rob Miller in the 1990s. Similar to other languages for reasoning about change, the event calculus represents the effects of actions on fluents. However, events can also be external to the system. In the event calculus, one can specify the value of fluents at some given time points, the events that take place at given time points, and their effects. Fluents and events In the event calculus, fluents are reified. This means that they are not formalized by means of predicates but by means of functions. A separate predicate is used to tell which fluents hold at a given time point. For example, \mathit(on(box,table),t) means that the box is on the table at time ; in this formula, is a predicate while is a function. Events are also represented as terms. The effects of events ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Situation Calculus
The situation calculus is a logic formalism designed for representing and reasoning about dynamical domains. It was first introduced by John McCarthy in 1963. The main version of the situational calculus that is presented in this article is based on that introduced by Ray Reiter in 1991. It is followed by sections about McCarthy's 1986 version and a logic programming formulation. Overview The situation calculus represents changing scenarios as a set of first-order logic formulae. The basic elements of the calculus are: *The actions that can be performed in the world *The fluents that describe the state of the world *The situations A domain is formalized by a number of formulae, namely: *Action precondition axioms, one for each action *Successor state axioms, one for each fluent *Axioms describing the world in various situations *The foundational axioms of the situation calculus A simple robot world will be modeled as a running example. In this world there is a single robot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluent Calculus
The fluent calculus is a formalism for expressing dynamical domains in first-order logic First-order logic—also known as predicate logic, quantificational logic, and first-order predicate calculus—is a collection of formal systems used in mathematics, philosophy, linguistics, and computer science. First-order logic uses quanti .... It is a variant of the situation calculus; the main difference is that situations are considered representations of states. A binary function symbol \circ is used to concatenate the terms that represent facts that hold in a situation. For example, that the box is on the table in the situation s is represented by the formula \exists t . s = on(box,table) \circ t. The frame problem is solved by asserting that the situation after the execution of an action is identical to the one before but for the conditions changed by the action. For example, the action of moving the box from the table to the floor is formalized as: : State(Do(move(box,table,flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GOLOG
Golog (Golok or Guoluo) Tibetan Autonomous Prefecture (; ) is an autonomous prefecture occupying the southeastern corner of Qinghai province, People's Republic of China. The prefecture has an area of and its seat is located in Maqên County. Due to its special geographical location and natural environment, the entire autonomous preference has been included in the Chinese largest natural environmental protection area — the Sanjiangyuan National Park. Geography Golog Prefecture is located in the southeastern part of Qinghai, in the upper basin of the Yellow River. Gyaring Lake and Ngoring Lake on the western edge of the prefecture are considered to be the source of the Yellow River. However, these lakes do receive water from rivers that flow from locations even further west, in Qumarleb County of the Yushu Tibetan Autonomous Prefecture. The lay of the land of the prefecture is largely determined by the Amne Machin Amne Machin, Anyi Machen, or Anyê Maqên ("Grandfa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Temporal Logic
In logic, linear temporal logic or linear-time temporal logic (LTL) is a modal temporal logic with modalities referring to time. In LTL, one can encode formulae about the future of paths, e.g., a condition will eventually be true, a condition will be true until another fact becomes true, etc. It is a fragment of the more complex CTL*, which additionally allows branching time and quantifiers. Subsequently, LTL is sometimes called ''propositional temporal logic'', abbreviated ''PTL''. In terms of expressive power, linear temporal logic (LTL) is a fragment of first-order logic. LTL was first proposed for the formal verification of computer programs by Amir Pnueli in 1977. Syntax LTL is built up from a finite set of propositional variables ''AP'', the logical operators ¬ and ∨, and the temporal modal operators X (some literature uses O or N) and U. Formally, the set of LTL formulas over ''AP'' is inductively defined as follows: * if p ∈ ''AP'' then p is an LTL formula; * if ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluent (artificial Intelligence)
In artificial intelligence, a fluent is a condition that can change over time. In logical approaches to reasoning about actions, fluents can be represented in first-order logic by predicates having an argument that depends on time. For example, the condition "the box is on the table", if it can change over time, cannot be represented by \mathrm(\mathrm,\mathrm); a third argument is necessary to the predicate \mathrm to specify the time: \mathrm(\mathrm,\mathrm,t) means that the box is on the table at time t. This representation of fluents is modified in the situation calculus by using the sequence of the past actions in place of the current time. A fluent can also be represented by a function, dropping the time argument. For example, that the box is on the table can be represented by on(box,table), where on is a function and not a predicate. In first order logic, converting predicates to functions is called reification; for this reason, fluents represented by functions are said t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boolean SAT
In logic and computer science, the Boolean satisfiability problem (sometimes called propositional satisfiability problem and abbreviated SATISFIABILITY, SAT or B-SAT) is the problem of determining if there exists an interpretation that satisfies a given Boolean formula. In other words, it asks whether the variables of a given Boolean formula can be consistently replaced by the values TRUE or FALSE in such a way that the formula evaluates to TRUE. If this is the case, the formula is called ''satisfiable''. On the other hand, if no such assignment exists, the function expressed by the formula is FALSE for all possible variable assignments and the formula is ''unsatisfiable''. For example, the formula "''a'' AND NOT ''b''" is satisfiable because one can find the values ''a'' = TRUE and ''b'' = FALSE, which make (''a'' AND NOT ''b'') = TRUE. In contrast, "''a'' AND NOT ''a''" is unsatisfiable. SAT is the first problem that was proved to be NP-complete; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
State Transition System
In theoretical computer science, a transition system is a concept used in the study of computation. It is used to describe the potential behavior of discrete systems. It consists of states and transitions between states, which may be labeled with labels chosen from a set; the same label may appear on more than one transition. If the label set is a singleton, the system is essentially unlabeled, and a simpler definition that omits the labels is possible. Transition systems coincide mathematically with abstract rewriting systems (as explained further in this article) and directed graphs. They differ from finite-state automata in several ways: * The set of states is not necessarily finite, or even countable. * The set of transitions is not necessarily finite, or even countable. * No "start" state or "final" states are given. Transition systems can be represented as directed graphs. Formal definition Formally, a transition system is a pair (S, \rightarrow) where S is a set o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
