let str_subs_dbg table (subs : t_subst list) (size : string) : string =
let rec help cnt str = function
| sub::subs -> help (cnt+1) (str^"---- subst ("^(string_of_int cnt)^"/"^size^") ----\n"^(str_sub_dbg table sub)) subs
| [] -> str
in
if subs = [] then "empty subst list\n" else help 1 "" subs