  Results of Bohr-Neugebauer type are obtained for recurrent functions : If $y$
is a bounded uniformly continuous solution of a linear neutral
difference-differential system with recurrent right-hand side, then $y$ is
recurrent if $c_0 \not \subset X$ ; also analogues and extensions to half lines
are given. For this, various subclasses "$rec$" are introduced which are linear
(the set REC of all recurrent functions is not), invariant, closed etc. Also,
analogues of the Bohl-Bohr-Amerio-Kadets and Esclangon- Landau results for REC
are obtained.
