| Definitions |  x:A. B(x), P   Q,  b, interface-compatible(A;B), [[R]], if b t else f fi, P & Q, Rnone?(x1), True, true , false, t  T, SQType(T), {T}, Prop, P  Q, P Q, ,  x. t(x), Dsys,  T, t ...$L, Realizer,  A, A || B, Y, P  Q, False, Unit, x(s), Dec(P), interface-link(A;B;l;tg),  , , left  right, @loc x initially v:T, @loc only events in L change x:T, only events in L send on lnk with tag, @loc effect knd(v:T) x := f State(ds) v , sends knd(v:T) on l:tagged(g,State(ds),v):dt, @loc precondition for a(v:T):P State(ds) v, @loc: k writes only members of L, @loc: k sends only on links in L, @loc: only members of L read x |