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An example of a non-transitive relation with a less meaningful transitive closure is "x is the day of the week after y". The transitive closure of this relation is "some day x comes after a day y on the calendar", which is trivially true for all days of the week x and y (and thus equivalent to the Cartesian square , which is " x and y are both ...
In mathematics, a binary relation R on a set X is transitive if, for all elements a, b, c in X, whenever R relates a to b and b to c, then R also relates a to c. Every partial order and every equivalence relation is transitive. For example, less than and equality among real numbers are both transitive: If a < b and b < c then a < c; and if x ...
For example, a grammar for a context-free language is left-recursive if there exists a non-terminal symbol A that can be put through the production rules to produce a string with A as the leftmost symbol. [15] An example of recursive grammar is a clause within a sentence separated by two commas. [16]
Various inequivalent definitions of Kleene algebras and related structures have been given in the literature. [5] Here we will give the definition that seems to be the most common nowadays. A Kleene algebra is a set A together with two binary operations + : A × A → A and · : A × A → A and one function * : A → A , written as a + b , ab ...
In matroid theory, the closure of X is the largest superset of X that has the same rank as X. The transitive closure of a set. [1] The algebraic closure of a field. [2] The integral closure of an integral domain in a field that contains it. The radical of an ideal in a commutative ring.
The Floyd–Warshall algorithm is an example of dynamic programming, and was published in its currently recognized form by Robert Floyd in 1962. [3] However, it is essentially the same as algorithms previously published by Bernard Roy in 1959 [4] and also by Stephen Warshall in 1962 [5] for finding the transitive closure of a graph, [6] and is closely related to Kleene's algorithm (published ...
A transitive set (or class) that is a model of a formal system of set theory is called a transitive model of the system (provided that the element relation of the model is the restriction of the true element relation to the universe of the model). Transitivity is an important factor in determining the absoluteness of formulas.
For example, if we start from a specific city x and apply the given transitive closure to yield the set of cities that can be reached from x, this set is closed in the sense that applying the same relation to any of those cities yields the same set again: you can't get to any other city but those in the set.