let str_subs_clot_dbg table (subs : t_subst list) (size : string) (u : term) (v : term) : string =
let rec help cnt str = function
| sub::subs ->
let pu,sub2 = purify sub u in
let pv,sub2 = purify sub2 v in
let u_clot = clot_light sub2 pu in
let v_clot = clot_light sub2 pv in
help (cnt+1)
(str^"---- subst ("^(string_of_int cnt)^"/"^size^") ----\n"^
(str_sub_clot_dbg table sub)^
"\nu(sub) = "^(str_term_dbg table u_clot)^
"\nv(sub) = "^(str_term_dbg table v_clot)^"\n"
) subs
| [] -> str
in
if subs = [] then "empty subst list\n" else help 1 "" subs