theory Command
imports Main
begin

ML {*
let
   val do_nothing = Scan.succeed (LocalTheory.theory I)
   val kind = OuterKeyword.thy_decl
in
   OuterSyntax.local_theory "foobar" "description of foobar" kind do_nothing
end
*}

ML {*
let
  fun trace_prop str =
     LocalTheory.theory (fn lthy => (tracing str; lthy))
  val trace_prop_parser = OuterParse.prop >> trace_prop
  val kind = OuterKeyword.thy_decl
in
  OuterSyntax.local_theory "foobar_trace" "traces a proposition"
    kind trace_prop_parser
end
*}

ML {*
let
   fun prove_prop str lthy =
     let
       val prop = Syntax.read_prop lthy str
     in
       Proof.theorem_i NONE (K I) [[(prop,[])]] lthy
     end;
   val prove_prop_parser = OuterParse.prop >> prove_prop
   val kind = OuterKeyword.thy_goal
in
   OuterSyntax.local_theory_to_proof "foobar_goal" "proving a proposition"
     kind prove_prop_parser
end
*}

ML {*
val r = ref (NONE:(unit -> term) option)
*}
ML {*
let
   fun setup_proof (txt, pos) lthy =
   let
     val trm = ML_Context.evaluate lthy true ("r", r) txt
   in
       Proof.theorem_i NONE (K I) [[(trm,[])]] lthy
   end;

   val setup_proof_parser = OuterParse.ML_source >> setup_proof
        
   val kind = OuterKeyword.thy_goal
in
   OuterSyntax.local_theory_to_proof "foobar_prove" "proving a proposition" 
    kind setup_proof_parser
end
*}

(*
ML {*
let
   val do_nothing = Scan.succeed (LocalTheory.theory I)
   val kind = OuterKeyword.thy_decl
in
   OuterSyntax.local_theory "simple_inductive" "description of foobar" kind do_nothing
end
*}*)

end