sidekick/src/core/Internal.mli
2017-12-29 17:24:09 +01:00

122 lines
4.2 KiB
OCaml

(*
MSAT is free software, using the Apache license, see file LICENSE
Copyright 2014 Guillaume Bury
Copyright 2014 Simon Cruanes
*)
(** mSAT core
This is the core of msat, containing the code doing the actual solving.
This module is based on mini-sat, and as such the solver heavily uses mutation,
which makes using it direclty kinda tricky (some exceptions can be raised
at surprising times, mutating is dangerous for maintaining invariants, etc...).
*)
module Make
(St : Solver_types.S)
(Th : Plugin_intf.S with type term = St.term
and type formula = St.formula and type proof = St.proof)
: sig
(** Functor to create a solver parametrised by the atomic formulas and a theory. *)
(** {2 Solving facilities} *)
exception Unsat
exception UndecidedLit
type t
(** Solver *)
val create : ?size:[`Tiny|`Small|`Big] -> ?st:St.t -> unit -> t
val st : t -> St.t
(** Underlying state *)
val solve : t -> unit
(** Try and solves the current set of assumptions.
@return () if the current set of clauses is satisfiable
@raise Unsat if a toplevel conflict is found *)
val assume : t -> ?tag:int -> St.formula list list -> unit
(** Add the list of clauses to the current set of assumptions.
Modifies the sat solver state in place. *)
val new_lit : t -> St.term -> unit
(** Add a new litteral (i.e term) to the solver. This term will
be decided on at some point during solving, wether it appears
in clauses or not. *)
val new_atom : t -> St.formula -> unit
(** Add a new atom (i.e propositional formula) to the solver.
This formula will be decided on at some point during solving,
wether it appears in clauses or not. *)
val push : t -> unit
(** Create a decision level for local assumptions.
@raise Unsat if a conflict is detected in the current state. *)
val pop : t -> unit
(** Pop a decision level for local assumptions. *)
val local : t -> St.formula list -> unit
(** Add local assumptions
@param assumptions list of additional local assumptions to make,
removed after the callback returns a value *)
(** {2 Propositional models} *)
val eval : t -> St.formula -> bool
(** Returns the valuation of a formula in the current state
of the sat solver.
@raise UndecidedLit if the literal is not decided *)
val eval_level : t -> St.formula -> bool * int
(** Return the current assignement of the literals, as well as its
decision level. If the level is 0, then it is necessary for
the atom to have this value; otherwise it is due to choices
that can potentially be backtracked.
@raise UndecidedLit if the literal is not decided *)
val model : t -> (St.term * St.term) list
(** Returns the model found if the formula is satisfiable. *)
val check : t -> bool
(** Check the satisfiability of the current model. Only has meaning
if the solver finished proof search and has returned [Sat]. *)
(** {2 Proofs and Models} *)
module Proof : Res.S with module St = St
val unsat_conflict : t -> St.clause option
(** Returns the unsat clause found at the toplevel, if it exists (i.e if
[solve] has raised [Unsat]) *)
val full_slice : t -> (St.term, St.formula, St.proof) Plugin_intf.slice
(** View the current state of the trail as a slice. Mainly useful when the
solver has reached a SAT conclusion. *)
(** {2 Internal data}
These functions expose some internal data stored by the solver, as such
great care should be taken to ensure not to mess with the values returned. *)
val trail : t -> St.trail_elt Vec.t
(** Returns the current trail.
*DO NOT MUTATE* *)
val hyps : t -> St.clause Vec.t
(** Returns the vector of assumptions used by the solver. May be slightly different
from the clauses assumed because of top-level simplification of clauses.
*DO NOT MUTATE* *)
val temp : t -> St.clause Vec.t
(** Returns the clauses coreesponding to the local assumptions.
All clauses in this vec are assured to be unit clauses.
*DO NOT MUTATE* *)
val history : t -> St.clause Vec.t
(** Returns the history of learnt clauses, with no guarantees on order.
*DO NOT MUTATE* *)
end