  In this paper, we show that theory of processes can be reduced to the theory
of spatial logic. Firstly, we propose a spatial logic SL for higher order
pi-calculus, and give an inference system of SL. The soundness and
incompleteness of SL are proved. Furthermore, we show that the structure
congruence relation and one-step transition relation can be described as the
logical relation of SL formulae. We also extend bisimulations for processes to
that for SL formulae. Then we extend all definitions and results of SL to a
weak semantics version of SL, called WL. At last, we add mu-operator to SL.
This new logic is named muSL. We show that WL is a sublogic of muSL and
replication operator can be expressed in muSL.
