Japanese Zen expressions of this selfless existence. Zen emphasizes zazen, meditation c.q. dhyana in astting position. In Soto, the emphasis is on shikantaza, 'just sitting', while Rinzai also uses koans to train the mind. In alternation with zazen, there is walking meditation, "kinhin", in which one walks with full attention. To facilitate insight, a Zen teacher can assign a kōan. This is a short anecdote, which seems irrational, but contains subtle references to the Buddhist teachings. An example of a kōan is Joshu's 'Mu': "A monk asked: "Does a dog have buddha-nature?" Joshu responded: "Mu!"" Zen-meditation aims at "non-thinking," in Japanese "fu
Reasoning system world assumption (OWA). The OWA is often associated with ontological knowledge representation and the Semantic Web. Different systems exhibit a variety of approaches to negation. As well as logical or bitwise complement, systems may support existential forms of strong and weak negation including negation-as-failure and ‘inflationary’ negation (negation of non-ground atoms). Different reasoning systems may support monotonic or non-monotonic reasoning, stratification and other logical techniques. Many reasoning systems provide capabilities for reasoning under uncertainty. This is important when building situated reasoning agents which must deal with uncertain representations of the world. There are several common approaches to handling uncertainty. These