In
computer science
Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, ...
, an action language is a language for specifying
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 wi ...
s, 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
Artificial intelligence (AI) is the capability of computer, computational systems to perform tasks typically associated with human intelligence, such as learning, reasoning, problem-solving, perception, and decision-making. It is a field of re ...
and
robotics
Robotics is the interdisciplinary study and practice of the design, construction, operation, and use of robots.
Within mechanical engineering, robotics is the design and construction of the physical structures of robots, while in computer s ...
domains, where they describe how actions affect the states of systems over time, and may be used for
automated planning
Automated planning and scheduling, sometimes denoted as simply AI planning, is a branch of artificial intelligence that concerns the realization of strategy, strategies or action sequences, typically for execution by intelligent agents, autonomou ...
.
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
answer set programs.
Since modern answer-set solvers make use of
boolean SAT algorithms to very rapidly ascertain
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 ...
, this implies that action languages can also enjoy the progress being made in the domain of boolean SAT solving.
Formal definition
All action languages supplement the definition of a
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 wi ...
with a set ''F'' of ''
fluents'', a set ''V'' of values that fluents may take, and a function mapping ''S'' × ''F'' to ''V'', where ''S'' is the set of states of a state transition system.
See also
*
Linear temporal logic
In logic, linear temporal logic or linear-time temporal logic (LTL) is a modal logic, modal temporal logic with modalities referring to time. In LTL, one can encode formula (logic), formulae about the future of path (graph theory), paths, e.g., a c ...
*
GOLOG
*
Fluent calculus
*
Situation calculus
*
Event calculus
References
{{DEFAULTSORT:Action Language
Programming language classification
Automated planning and scheduling
Transition systems