preimage

suomi-englanti sanakirja

preimage englanniksi

  1. For a given function, the set of all elements of the domain that are mapped into a given subset of the codomain; given a function ƒ : ''X'' → ''Y'' and a subset ''B'' ⊆ ''Y'', the set ƒ−1(''B'') = {''x'' ∈ ''X'' : ƒ(''x'') ∈ ''B''}.

  2. 1967 Press, Francois Treves, ''Topological Vector Spaces, Distributions and Kernels'', 2006, Dover, page 22,

  3. The preimage of a neighborhood ''U'' of 0 in ''E'' must be a neighborhood of (0,''x''), since (0,''x'') is mapped into 0.
  4. 2003, Sergei K. Lando, Alexander K. Zvonkin, ''Graphs on Surfaces and Their Applications'', Springer, page 56,

  5. Previously, maps and hypermaps were constructed as the preimages of a segment joining two of the three critical values.
  6. 2005, Oded Goldreich, ''Foundations of Cryptography: A Primer'', now Publishers, page 24,

  7. Loosely speaking, saying that a function ''f'' is one-way implies that given ''y'' (in the range of ''f'') it is infeasible to find a preimage of ''y'' under ''f''.