A proposition or truth value is semi-decidable or semidecidable if and only if there exists a sequence of booleans such that if and only if there exists a natural number such that .
The set of all semi-decidable propositions is typically called the Rosolini dominance, though it may not be a dominance without certain assumptions such as countable choice or excluded middle.
If the foundations of mathematics has the Cauchy real numbers as well, then is semideciable if and only if there exists a Cauchy real number such that if and only if .
The limited principle of omniscience for the natural numbers implies that every semi-decidable proposition is a decidable proposition.
Last revised on January 27, 2024 at 18:07:40. See the history of this page for a list of all contributions to it.