at src(l):
action $a(m)
precondition P psends [$tg,f] on link l == ([@source(l) precondition for "$a"(v:A):
== ([@source(l) P State(ds) v
== (; sends locl("$a")(v:A) on l:
== (; tagged([<"$tg",s,v. [f(s,v)]>],State(ds),v):"$tg" : T == (; only events in [locl("$a")] send on l with "$tg"])
weakPrecondSendR{$a,$tg}(T;A;l;ds;P;f)
== ([@source(l) precondition for "$a"(v:A):
== ([@source(l) P State(ds) v
== (; sends locl("$a")(v:A) on l:
== (; tagged(<"$tg",s,v. (f(s,v)).nil>.nil,State(ds),v):"$tg" : T == (/ only events in locl("$a").nil send on l with "$tg".nil])