Original sentence: In functional analysis a partial isometry is a linear map W between Hilbert spaces H and K such that the restriction of W to the orthogonal complement of its kernel is an isometry.pl:Częściowa izometria
Edited sentence: "Inverse semigroups: the theory of partial symmetries".Lawson (1998).Mark V.Partial isometries can be defined in the more abstract setting of a semigroup with involution; the definition concides with the one herein.World Scientific ISBN 9810233167.pl:Częściowa izometriaIn functional analysis a partial isometry is a linear map W between Hilbert spaces H and K such that the restriction of W to the orthogonal complement of its kernel is an isometry