Update PGIP packet handling, fixing unique session identifier.
(* legacy ML bindings *)
val less_fun_def = thm "less_fun_def";
val refl_less_fun = thm "refl_less_fun";
val antisym_less_fun = thm "antisym_less_fun";
val trans_less_fun = thm "trans_less_fun";
val minimal_fun = thm "minimal_fun";
val least_fun = thm "least_fun";
val less_fun = thm "less_fun";
val ch2ch_fun = thm "ch2ch_fun";
val ub2ub_fun = thm "ub2ub_fun";
val lub_fun = thm "lub_fun";
val thelub_fun = thm "thelub_fun";
val cpo_fun = thm "cpo_fun";
val inst_fun_pcpo = thm "inst_fun_pcpo";