an C behavior R consists of:
a time set F;
a nonempty set V called the control-value or input-value space V;
a nonempty set B called the output-value or measurement-value space of B; and
a map G called the response map of G, which is defined on a nonempty subset G of G, such that the following property holds:
restriction
if T is in T, then also T for each T.