Definitions | t T, x:A. B(x), es is an event system of D, ES, Type, {x:A| B(x) }, x:A B(x), @i only events in L change x : T, Prop, x.A(x), {T}, P  Q,  x. t(x), Dsys, D1 D2, D realizes es. P(es), A & B, Id, , MsgA, a = b, if b t else f fi, @i: A, Knd, type List, @i: only L affects x : t, only members of L affect x :t |