Abstract:
Giammarresi & Restivo (1992) define locality and recognizability for 2-dimensional
languages. Based on these notions, generalized to the n-dimensional case,
n-dimensionally colorable 1-dimensional languages are introduced.
It is shown: A language L is in NP if and only if L is n-dimensionally colorable for some n.
An analogous characterization in terms of deterministic n-dimensional colorability, based
on a definition of 2-dimensional deterministic recognizability from Reinhardt (1998), is
obtained for P. For an analogous characterization of PSPACE one unbounded dimension
for coloring is added.