Hybrid systems are interactive systems of continuous devices and digital control programs. Typical examples are digital modules that control a physical environment evolving over time. The principal problem of the subject is to model them so that given a specification for the continuous component of the system, we can extract, if this is possible, from the description of the total system and the specification of the continuous component, the specification of thecontrol program which will force the continuous device to meet its specification.This paper presents a formal description language for hybrid sys- tems, which is an integration of CSP, which describes digital control programs, and DC for specification of continuous devices. We define primitive operators over systems in DC and prove that so defined operators meet basic algebraic laws of these operators.