enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Necessity and sufficiency - Wikipedia

    en.wikipedia.org/wiki/Necessity_and_sufficiency

    This can also be expressed as "P only if Q", "P implies Q" or several other variants. It may be the case that several sufficient conditions, when taken together, constitute a single necessary condition (i.e., individually sufficient and jointly necessary), as illustrated in example 5. Example 1 "John is a king" implies that John is male.

  3. Order of operations - Wikipedia

    en.wikipedia.org/wiki/Order_of_operations

    In mathematics and computer programming, the order of operations is a collection of rules that reflect conventions about which operations to perform first in order to evaluate a given mathematical expression. These rules are formalized with a ranking of the operations.

  4. English modal auxiliary verbs - Wikipedia

    en.wikipedia.org/wiki/English_modal_auxiliary_verbs

    The English modal auxiliary verbs are a subset of the English auxiliary verbs used mostly to express modality, properties such as possibility and obligation. [a] They can most easily be distinguished from other verbs by their defectiveness (they do not have participles or plain forms [b]) and by their lack of the ending ‑(e)s for the third-person singular.

  5. Modal verb - Wikipedia

    en.wikipedia.org/wiki/Modal_verb

    The primary meaning would be the deontic meaning ("You are required to speak Spanish.") but this may be intended epistemically ("It is surely the case that you speak Spanish"). Epistemic modals can be analyzed as raising verbs, while deontic modals can be analyzed as control verbs. Epistemic usages of modals tend to develop from deontic usages. [4]

  6. Direct proof - Wikipedia

    en.wikipedia.org/wiki/Direct_proof

    The earliest form of mathematics was phenomenological. For example, if someone could draw a reasonable picture, or give a convincing description, then that met all the criteria for something to be described as a mathematical “fact”. On occasion, analogical arguments took place, or even by “invoking the gods”. The idea that mathematical ...

  7. Law (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Law_(mathematics)

    The rules allow the expression of conjunctions and disjunctions purely in terms of each other via negation. The rules can be expressed in English as: not (A or B) = (not A) and (not B) not (A and B) = (not A) or (not B) where "A or B" is an "inclusive or" meaning at least one of A or B rather than an "exclusive or" that means exactly one

  8. Converse (logic) - Wikipedia

    en.wikipedia.org/wiki/Converse_(logic)

    The converse may or may not be true, and even if true, the proof may be difficult. For example, the four-vertex theorem was proved in 1912, but its converse was proved only in 1997. [3] In practice, when determining the converse of a mathematical theorem, aspects of the antecedent may be taken as establishing context.

  9. Mathematical proof - Wikipedia

    en.wikipedia.org/wiki/Mathematical_proof

    The definition of a formal proof is intended to capture the concept of proofs as written in the practice of mathematics. The soundness of this definition amounts to the belief that a published proof can, in principle, be converted into a formal proof. However, outside the field of automated proof assistants, this is rarely done in practice.