Indeterminacy is a property of

formal system A formal system is an abstract structure used for inferring theorems from axioms according to a set of rules. These rules, which are used for carrying out the inference of theorems from axioms, are the logical calculus of the formal system. A form ...

s that evolve in time (often conceptualized as a

computation Computation is any type of arithmetic or non-arithmetic calculation that follows a well-defined model (e.g., an algorithm). Mechanical or electronic devices (or, historically, people) that perform computations are known as ''computers''. An es ...

), in which complete information about the ''internal'' state of the system at some point in time admits multiple future trajectories. In simpler terms, if such a system is returned to the same initial condition—or two identical copies of the system are started at the same time—they won't with certainty produce the same behaviour, as some element of chance is able to enter the system from outside its formal specification. In some cases the indeterminacy arises from the laws of

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

, in other cases it leaks in from the abstract model, and sometimes the model includes an explicit source of indeterminacy, as with deliberately

randomized algorithm A randomized algorithm is an algorithm that employs a degree of randomness as part of its logic or procedure. The algorithm typically uses uniformly random bits as an auxiliary input to guide its behavior, in the hope of achieving good performan ...

s, for the benefits that this provides.

Disambiguation

Indeterminancy in computation may refer to: *

quantum indeterminacy Quantum indeterminacy is the apparent ''necessary'' incompleteness in the description of a physical system, that has become one of the characteristics of the standard description of quantum physics. Prior to quantum physics, it was thought that : ...

in quantum computers * nondeterministic finite automata *

nondeterministic algorithm In computer programming, a nondeterministic algorithm is an algorithm that, even for the same input, can exhibit different behaviors on different runs, as opposed to a deterministic algorithm. There are several ways an algorithm may behave diffe ...

In concurrency: *

indeterminacy in concurrent computation Indeterminacy in concurrent computation is concerned with the effects of indeterminacy in concurrent computation. Computation is an area in which indeterminacy is becoming increasingly important because of the massive increase in concurrency due ...

unbounded nondeterminism In computer science, unbounded nondeterminism or unbounded indeterminacy is a property of concurrency by which the amount of delay in servicing a request can become unbounded as a result of arbitration of contention for shared resources ''while ...

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