(* Title: Tools/solve_direct.ML
Author: Timothy Bourke and Gerwin Klein, NICTA
Check whether a newly stated theorem can be solved directly by an
existing theorem. Duplicate lemmas can be detected in this way.
The implementation relies critically on the Find_Theorems solves
feature.
*)
signature SOLVE_DIRECT =
sig
val solve_directN: string
val someN: string
val noneN: string
val unknownN: string
val max_solutions: int Config.T
val strict_warnings: bool Config.T
val solve_direct: Proof.state -> bool * (string * string list)
end;
structure Solve_Direct: SOLVE_DIRECT =
struct
datatype mode = Auto_Try | Try | Normal
val solve_directN = "solve_direct";
val someN = "some";
val noneN = "none";
val unknownN = "none";
(* preferences *)
val max_solutions = Attrib.setup_config_int @{binding solve_direct_max_solutions} (K 5);
val strict_warnings = Attrib.setup_config_bool @{binding solve_direct_strict_warnings} (K false);
(* solve_direct command *)
fun do_solve_direct mode state =
let
val ctxt = Proof.context_of state;
val find_ctxt = if mode = Auto_Try then Context_Position.set_visible false ctxt else ctxt;
val crits = [(true, Find_Theorems.Solves)];
fun find g =
snd (Find_Theorems.find_theorems find_ctxt (SOME g)
(SOME (Config.get find_ctxt max_solutions)) false crits);
fun prt_result (goal, results) =
let
val msg =
(if mode = Auto_Try then "Auto " else "") ^ solve_directN ^ ": " ^
(case goal of
NONE => "The current goal"
| SOME sg => Syntax.string_of_term ctxt (Thm.term_of sg));
in
Pretty.big_list
(msg ^ " can be solved directly with")
(map (Find_Theorems.pretty_thm ctxt) results)
end;
fun seek_against_goal () =
(case try Proof.simple_goal state of
NONE => NONE
| SOME {goal = st, ...} =>
let
val subgoals = Drule.strip_imp_prems (Thm.cprop_of st);
val rs =
if length subgoals = 1
then [(NONE, find st)]
else map (fn sg => (SOME sg, find (Goal.init sg))) subgoals;
val results = filter_out (null o snd) rs;
in if null results then NONE else SOME results end);
fun message results = separate (Pretty.brk 0) (map prt_result results);
in
(case try seek_against_goal () of
SOME (SOME results) =>
(someN,
let
val msg = Pretty.string_of (Pretty.chunks (message results))
in
if Config.get ctxt strict_warnings
then (warning msg; [])
else if mode = Auto_Try
then [msg]
else (writeln msg; [])
end)
| SOME NONE =>
(if mode = Normal then writeln "No proof found"
else ();
(noneN, []))
| NONE =>
(if mode = Normal then writeln "An error occurred"
else ();
(unknownN, [])))
end
|> `(fn (outcome_code, _) => outcome_code = someN);
val solve_direct = do_solve_direct Normal
val _ =
Outer_Syntax.command @{command_keyword solve_direct}
"try to solve conjectures directly with existing theorems"
(Scan.succeed (Toplevel.keep_proof (ignore o solve_direct o Toplevel.proof_of)));
(* hook *)
fun try_solve_direct auto = do_solve_direct (if auto then Auto_Try else Try)
val _ = Try.tool_setup (solve_directN, (10, @{system_option auto_solve_direct}, try_solve_direct));
end;