(*  Title:      HOL/SMT/Tools/cvc3_solver.ML

    Author:     Sascha Boehme, TU Muenchen

Interface of the SMT solver CVC3.

*)

signature CVC3_SOLVER =

sig

  val setup: theory -> theory

end

structure CVC3_Solver: CVC3_SOLVER =

struct

val solver_name = "cvc3"

val env_var = "CVC3_SOLVER"

val options =

  ["+counterexample", "-lang", "smtlib", "-output-lang", "presentation"]

val is_sat = String.isPrefix "Satisfiable."

val is_unsat = String.isPrefix "Unsatisfiable."

val is_unknown = String.isPrefix "Unknown."

fun cex_kind true = "Counterexample"

  | cex_kind false = "Possible counterexample"

fun raise_cex real ctxt recon ls =

  let

    val start = String.isPrefix "%Satisfiable  Variable Assignment: %"

    val index = find_index start ls

    val ls = if index > 0 then Library.drop (index + 1, ls) else []

    val p = Pretty.big_list (cex_kind real ^ " found:") (map Pretty.str ls)

  in error (Pretty.string_of p) end

fun core_oracle (SMT_Solver.ProofData {context, output, recon, ...}) =

  let

    val empty_line = (fn "" => true | _ => false)

    val split_first = (fn [] => ("", []) | l :: ls => (l, ls))

    val (l, ls) = split_first (dropwhile empty_line output)

  in

    if is_unsat l then @{cprop False}

    else if is_sat l then raise_cex true context recon ls

    else if is_unknown l then raise_cex false context recon ls

    else error (solver_name ^ " failed")

  end

fun smtlib_solver oracle _ =

  SMT_Solver.SolverConfig {

    name = {env_var=env_var, remote_name=solver_name},

    interface = SMTLIB_Interface.interface,

    arguments = options,

    reconstruct = oracle }

val setup =

  Thm.add_oracle (Binding.name solver_name, core_oracle) #-> (fn (_, oracle) =>

  SMT_Solver.add_solver (solver_name, smtlib_solver oracle))

end