(CDS) A model of programming language terms developed in
the context of constructing fully abstract semantics for
sequential languages. A CDS is a 4-tuple (C,V,E,|-) where C is
a cell, V is a value, E is an event and |- is an "enabling
relation". An event is a cell and a value. A cell C is "enabled"
by a set of events S if S |- C. A state is a set of events which
are consistent in that the values they give for any cell are all
equal. Every cell in a state is enabled.

[G. Berry, P.-L. Curien, "Theory and practice of sequential
algorithms: the kernel of applicative language CDS", Algebraic
methods in semantics, CUP 1985].