let rec pcml = function
| [] -> ()
| "-p"::optn::l -> _p := optn ; pcml l
| "-t"::optn::l -> _t := optn ; pcml l
| "-rp"::optn::l -> _rp := optn ; pcml l
| "-rt"::optn::l -> _rt := optn ; pcml l
| "-o"::optn::l -> _opacity := get_opacity optn ; pcml l
| "--no-blank"::l -> _no_blank := true ; pcml l
| "--help"::[s] -> init(); disp_welcome (); request_help_page s ; exit 0
| "--help"::l -> disp_help(); exit 0
| "--docu"::l -> init(); disp_welcome (); disp_doc(); exit 0
| "--predicates"::l -> init(); disp_welcome (); disp_preds () ; exit 0
| "--transforms"::l -> init(); disp_welcome (); disp_trans () ; exit 0
| "--funs"::l -> init (); disp_welcome (); disp_preds () ; pl "" ; disp_trans () ; pl ""; exit 0
| _ -> bad_args () ; failwith "Please correct the command-line and try again... (see --help)"