Added support for making constants final, that is, ensuring that no
definition can be given later (useful for constants whose behaviour is
fixed axiomatically rather than definitionally).
(* Title: HOL/Tools/specification_package.ML
ID: $Id$
Author: Sebastian Skalberg, TU Muenchen
License: GPL (GNU GENERAL PUBLIC LICENSE)
Package for defining constants by specification.
*)
signature SPECIFICATION_PACKAGE =
sig
val quiet_mode: bool ref
val add_specification_i: string option -> (bstring * xstring * bool) list
-> theory * thm -> theory * thm
end
structure SpecificationPackage : SPECIFICATION_PACKAGE =
struct
(* messages *)
val quiet_mode = ref false
fun message s = if ! quiet_mode then () else writeln s
local
val _ = Goal "[| Ex P ; c == Eps P |] ==> P c"
val _ = by (Asm_simp_tac 1)
val _ = by (rtac (thm "someI_ex") 1)
val _ = ba 1
in
val helper = Goals.result()
end
(* Akin to HOLogic.exists_const *)
fun choice_const T = Const("Hilbert_Choice.Eps",(T-->HOLogic.boolT)-->T)
(* Actual code *)
local
fun mk_definitional [] arg = arg
| mk_definitional ((thname,cname,covld)::cos) (thy,thm) =
case HOLogic.dest_Trueprop (concl_of thm) of
Const("Ex",_) $ P =>
let
val ctype = domain_type (type_of P)
val cname_full = Sign.intern_const (sign_of thy) cname
val cdefname = if thname = ""
then Thm.def_name (Sign.base_name cname)
else thname
val def_eq = Logic.mk_equals (Const(cname_full,ctype),choice_const ctype $ P)
val (thy',thms) = PureThy.add_defs_i covld [((cdefname,def_eq),[])] thy
val thm' = [thm,hd thms] MRS helper
in
mk_definitional cos (thy',thm')
end
| _ => raise THM ("Internal error: Bad specification theorem",0,[thm])
fun mk_axiomatic axname cos arg =
let
fun process [] (thy,tm) =
let
val (thy',thms) = PureThy.add_axioms_i [((axname,HOLogic.mk_Trueprop tm),[])] thy
in
(thy',hd thms)
end
| process ((thname,cname,covld)::cos) (thy,tm) =
case tm of
Const("Ex",_) $ P =>
let
val ctype = domain_type (type_of P)
val cname_full = Sign.intern_const (sign_of thy) cname
val cdefname = if thname = ""
then Thm.def_name (Sign.base_name cname)
else thname
val co = Const(cname_full,ctype)
val thy' = Theory.add_finals_i covld [co] thy
val tm' = case P of
Abs(_, _, bodt) => subst_bound (co, bodt)
| _ => P $ co
in
process cos (thy',tm')
end
| _ => raise TERM ("Internal error: Bad specification theorem",[tm])
in
process cos arg
end
in
fun proc_exprop axiomatic cos arg =
case axiomatic of
Some axname => mk_axiomatic axname cos (apsnd (HOLogic.dest_Trueprop o concl_of) arg)
| None => mk_definitional cos arg
end
fun add_specification_i axiomatic cos arg =
arg |> apsnd freezeT
|> proc_exprop axiomatic cos
|> apsnd standard
(* Collect all intances of constants in term *)
fun collect_consts ( t $ u,tms) = collect_consts (u,collect_consts (t,tms))
| collect_consts ( Abs(_,_,t),tms) = collect_consts (t,tms)
| collect_consts (tm as Const _,tms) = gen_ins (op aconv) (tm,tms)
| collect_consts ( _,tms) = tms
(* Complementing Type.varify... *)
fun unvarify t fmap =
let
val fmap' = map Library.swap fmap
fun unthaw (f as (a,S)) =
(case assoc (fmap',a) of
None => TVar f
| Some b => TFree (b,S))
in
map_term_types (map_type_tvar unthaw) t
end
(* The syntactic meddling needed to setup add_specification for work *)
fun process_spec axiomatic cos alt_props int thy =
let
fun zip3 [] [] [] = []
| zip3 (x::xs) (y::ys) (z::zs) = (x,y,z)::zip3 xs ys zs
| zip3 _ _ _ = error "SpecificationPackage.process_spec internal error"
fun myfoldr f [x] = x
| myfoldr f (x::xs) = f (x,myfoldr f xs)
| myfoldr f [] = error "SpecificationPackage.process_spec internal error"
val sg = sign_of thy
fun typ_equiv t u =
let
val tsig = Sign.tsig_of sg
in
Type.typ_instance(tsig,t,u) andalso
Type.typ_instance(tsig,u,t)
end
val cprops = map (Thm.read_cterm sg o rpair Term.propT o snd) alt_props
val ss = empty_ss setmksimps single addsimps [thm "HOL.atomize_imp",thm "HOL.atomize_all"]
val rew_imps = map (Simplifier.full_rewrite ss) cprops
val props' = map (HOLogic.dest_Trueprop o term_of o snd o dest_equals o cprop_of) rew_imps
fun proc_single prop =
let
val frees = Term.term_frees prop
val tsig = Sign.tsig_of (sign_of thy)
val _ = assert (forall (fn v => Type.of_sort tsig (type_of v,HOLogic.typeS)) frees)
"Specificaton: Only free variables of sort 'type' allowed"
val prop_closed = foldr (fn ((vname,T),prop) => HOLogic.mk_all (vname,T,prop)) (map dest_Free frees,prop)
in
(prop_closed,frees)
end
val props'' = map proc_single props'
val frees = map snd props''
val prop = myfoldr HOLogic.mk_conj (map fst props'')
val cprop = cterm_of sg (HOLogic.mk_Trueprop prop)
val (prop_thawed,vmap) = Type.varify (prop,[])
val thawed_prop_consts = collect_consts (prop_thawed,[])
val (altcos,overloaded) = Library.split_list cos
val (names,sconsts) = Library.split_list altcos
val consts = map (term_of o Thm.read_cterm sg o rpair TypeInfer.logicT) sconsts
val _ = assert (not (Library.exists (not o Term.is_Const) consts))
"Specification: Non-constant found as parameter"
fun proc_const c =
let
val c' = fst (Type.varify (c,[]))
val (cname,ctyp) = dest_Const c'
in
case filter (fn t => let val (name,typ) = dest_Const t
in name = cname andalso typ_equiv typ ctyp
end) thawed_prop_consts of
[] => error ("Specification: No suitable instances of constant \"" ^ (Sign.string_of_term sg c) ^ "\" found")
| [cf] => unvarify cf vmap
| _ => error ("Specification: Several variations of \"" ^ (Sign.string_of_term sg c) ^ "\" found (try applying explicit type constraints)")
end
val proc_consts = map proc_const consts
fun mk_exist (c,prop) =
let
val T = type_of c
val cname = Sign.base_name (fst (dest_Const c))
val vname = if Syntax.is_identifier cname
then cname
else "x"
in
HOLogic.exists_const T $ Abs(vname,T,Term.abstract_over (c,prop))
end
val ex_prop = foldr mk_exist (proc_consts,prop)
val cnames = map (fst o dest_Const) proc_consts
fun post_process (arg as (thy,thm)) =
let
fun inst_all sg (thm,v) =
let
val cv = cterm_of sg v
val cT = ctyp_of_term cv
val spec' = instantiate' [Some cT] [None,Some cv] spec
in
thm RS spec'
end
fun remove_alls frees thm = foldl (inst_all (sign_of_thm thm)) (thm,frees)
fun process_single ((name,atts),rew_imp,frees) args =
let
fun undo_imps thm =
equal_elim (symmetric rew_imp) thm
fun apply_atts arg = Thm.apply_attributes (arg,map (Attrib.global_attribute thy) atts)
fun add_final (arg as (thy,thm)) =
if name = ""
then arg
else (writeln (" " ^ name ^ ": " ^ (string_of_thm thm));
PureThy.store_thm((name,thm),[]) thy)
in
args |> apsnd (remove_alls frees)
|> apsnd undo_imps
|> apsnd standard
|> apply_atts
|> add_final
end
fun process_all [proc_arg] args =
process_single proc_arg args
| process_all (proc_arg::rest) (thy,thm) =
let
val single_th = thm RS conjunct1
val rest_th = thm RS conjunct2
val (thy',_) = process_single proc_arg (thy,single_th)
in
process_all rest (thy',rest_th)
end
| process_all [] _ = error "SpecificationPackage.process_spec internal error"
val alt_names = map fst alt_props
val _ = if exists (fn(name,_) => not (name = "")) alt_names
then writeln "specification"
else ()
in
arg |> apsnd freezeT
|> process_all (zip3 alt_names rew_imps frees)
end
in
IsarThy.theorem_i Drule.internalK
(("",[add_specification_i axiomatic (zip3 names cnames overloaded),post_process]),
(HOLogic.mk_Trueprop ex_prop,([],[]))) int thy
end
(* outer syntax *)
local structure P = OuterParse and K = OuterSyntax.Keyword in
(* taken from ~~/Pure/Isar/isar_syn.ML *)
val opt_overloaded =
Scan.optional (P.$$$ "(" |-- P.!!! ((P.$$$ "overloaded" >> K true) --| P.$$$ ")")) false
val opt_name = Scan.optional (P.name --| P.$$$ ":") ""
val specification_decl =
P.$$$ "(" |-- Scan.repeat1 (opt_name -- P.term -- opt_overloaded) --| P.$$$ ")" --
Scan.repeat1 (P.opt_thm_name ":" -- P.prop)
val specificationP =
OuterSyntax.command "specification" "define constants by specification" K.thy_goal
(specification_decl >> (fn (cos,alt_props) =>
Toplevel.print o (Toplevel.theory_to_proof
(process_spec None cos alt_props))))
val ax_specification_decl =
P.name --
(P.$$$ "(" |-- Scan.repeat1 (opt_name -- P.term -- opt_overloaded) --| P.$$$ ")" --
Scan.repeat1 (P.opt_thm_name ":" -- P.prop))
val ax_specificationP =
OuterSyntax.command "ax_specification" "define constants by specification" K.thy_goal
(ax_specification_decl >> (fn (axname,(cos,alt_props)) =>
Toplevel.print o (Toplevel.theory_to_proof
(process_spec (Some axname) cos alt_props))))
val _ = OuterSyntax.add_parsers [specificationP,ax_specificationP]
end
end