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Notation. half arrow upwards

  1. Oct 14, 2007 #1
    I encountered notation that I don't know. It's like T|A where T is a mapping, and A is a set (little like a restriction), but the | is an arrow pointing upwards and the left hook is missing like with an arrow of a weak convergence.

    Anyone knowing what that means? Or a keyword that I could put in google (I cannot put that half arrow there)
  2. jcsd
  3. Oct 14, 2007 #2


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    What is the context?
  4. Oct 14, 2007 #3
    Operators. T:X->X is a continuous linear mapping in a Banach space, and an ascent of the operator is defined

    \textrm{ascent}(T) := \textrm{min}\;\{p\in\mathbb{N}\;|\; \textrm{ker}(T^p)=\textrm{ker}(T^{p+1})\}

    The p is then assumed to be the ascent, and the notation

    T\upharpoonright T^p(X)

    is used. This notation means some kind of mapping, because it is said to be invertible.
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