When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Friendly number - Wikipedia

    en.wikipedia.org/wiki/Friendly_number

    A number that is not part of any friendly pair is called solitary. The abundancy index of n is the rational number σ(n) / n, in which σ denotes the sum of divisors function. A number n is a friendly number if there exists m ≠ n such that σ(m) / m = σ(n) / n. Abundancy is not the same as abundance, which is defined as σ(n) − 2n.

  3. Comparability - Wikipedia

    en.wikipedia.org/wiki/Comparability

    Hasse diagram of the natural numbers, partially ordered by "x≤y if x divides y".The numbers 4 and 6 are incomparable, since neither divides the other. In mathematics, two elements x and y of a set P are said to be comparable with respect to a binary relation ≤ if at least one of x ≤ y or y ≤ x is true.

  4. Equinumerosity - Wikipedia

    en.wikipedia.org/wiki/Equinumerosity

    Equinumerosity is compatible with the basic set operations in a way that allows the definition of cardinal arithmetic. [1] Specifically, equinumerosity is compatible with disjoint unions: Given four sets A, B, C and D with A and C on the one hand and B and D on the other hand pairwise disjoint and with A ~ B and C ~ D then A ∪ C ~ B ∪ D.

  5. Congruence relation - Wikipedia

    en.wikipedia.org/wiki/Congruence_relation

    In abstract algebra, a congruence relation (or simply congruence) is an equivalence relation on an algebraic structure (such as a group, ring, or vector space) that is compatible with the structure in the sense that algebraic operations done with equivalent elements will yield equivalent elements. [1]

  6. Ordered field - Wikipedia

    en.wikipedia.org/wiki/Ordered_field

    In mathematics, an ordered field is a field together with a total ordering of its elements that is compatible with the field operations. Basic examples of ordered fields are the rational numbers and the real numbers, both with their standard orderings. Every subfield of an ordered field is also an ordered field in the inherited order.

  7. Algebraic structure - Wikipedia

    en.wikipedia.org/wiki/Algebraic_structure

    Topological vector space: a vector space whose M has a compatible topology. Normed vector space: a vector space with a compatible norm. If such a space is complete (as a metric space) then it is called a Banach space. Hilbert space: an inner product space over the real or complex numbers whose inner product gives rise to a Banach space structure.

  8. AOL Mail

    mail.aol.com/?icid=aol.com-nav

    Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!

  9. Compatibility (mechanics) - Wikipedia

    en.wikipedia.org/wiki/Compatibility_(mechanics)

    In continuum mechanics, a compatible deformation (or strain) tensor field in a body is that unique tensor field that is obtained when the body is subjected to a continuous, single-valued, displacement field. Compatibility is the study of the conditions under which such a displacement field can be guaranteed.