is mentioned by

Def [[s]] rho == < op.[[s.fun(op)]] rho,R.[[s.rel(R)]] rho >	[sig_mng]
Def term_types(ds;da;de;t) == iterate(statevar x- > dec_lookup(ds;x) statevar x'- > dec_lookup(ds;x) funsymbol op- > < de.fun(op) > freevar x- > da trace(P)- > < lbl_pr( < Trace, P > ) > c1(c2)- > st_app(c1;c2) over t)	[term_types]

Try larger context: GenAutomata