is mentioned by

Def No-dup-send(E)(tr) == i,j:||tr||. (is-send(E)(tr[i])) (is-send(E)(tr[j])) (tr[i] =msg=(E) tr[j]) i = j	[no_duplicate_send]
Def tag_splitable(E;R) == tr_1,tr_2:Trace(E). (tr_1 R tr_2) (m:Label. < tr_1 > _m R < tr_2 > _m)	[tag_splitable]

In prior sections: core fun 1 well fnd int 1 bool 1 rel 1 sqequal 1 int 2 list 1 prog 1 mb basic mb nat union num thy 1 mb list 1 mb label mb list 2

Try larger context: GenAutomata