(* Title: HOL/Product_Type.thy
ID: $Id$
Author: Lawrence C Paulson, Cambridge University Computer Laboratory
Copyright 1992 University of Cambridge
*)
header {* Cartesian products *}
theory Product_Type
imports Inductive
uses
("Tools/split_rule.ML")
("Tools/inductive_set_package.ML")
("Tools/inductive_realizer.ML")
("Tools/datatype_realizer.ML")
begin
subsection {* @{typ bool} is a datatype *}
rep_datatype bool
distinct True_not_False False_not_True
induction bool_induct
declare case_split [cases type: bool]
-- "prefer plain propositional version"
subsection {* Unit *}
typedef unit = "{True}"
proof
show "True : ?unit" ..
qed
definition
Unity :: unit ("'(')")
where
"() = Abs_unit True"
lemma unit_eq [noatp]: "u = ()"
by (induct u) (simp add: unit_def Unity_def)
text {*
Simplification procedure for @{thm [source] unit_eq}. Cannot use
this rule directly --- it loops!
*}
ML_setup {*
val unit_eq_proc =
let val unit_meta_eq = mk_meta_eq @{thm unit_eq} in
Simplifier.simproc @{theory} "unit_eq" ["x::unit"]
(fn _ => fn _ => fn t => if HOLogic.is_unit t then NONE else SOME unit_meta_eq)
end;
Addsimprocs [unit_eq_proc];
*}
lemma unit_induct [noatp,induct type: unit]: "P () ==> P x"
by simp
rep_datatype unit
induction unit_induct
lemma unit_all_eq1: "(!!x::unit. PROP P x) == PROP P ()"
by simp
lemma unit_all_eq2: "(!!x::unit. PROP P) == PROP P"
by (rule triv_forall_equality)
text {*
This rewrite counters the effect of @{text unit_eq_proc} on @{term
[source] "%u::unit. f u"}, replacing it by @{term [source]
f} rather than by @{term [source] "%u. f ()"}.
*}
lemma unit_abs_eta_conv [simp,noatp]: "(%u::unit. f ()) = f"
by (rule ext) simp
subsection {* Pairs *}
subsubsection {* Type definition *}
constdefs
Pair_Rep :: "['a, 'b] => ['a, 'b] => bool"
"Pair_Rep == (%a b. %x y. x=a & y=b)"
global
typedef (Prod)
('a, 'b) "*" (infixr "*" 20)
= "{f. EX a b. f = Pair_Rep (a::'a) (b::'b)}"
proof
fix a b show "Pair_Rep a b : ?Prod"
by blast
qed
syntax (xsymbols)
"*" :: "[type, type] => type" ("(_ \<times>/ _)" [21, 20] 20)
syntax (HTML output)
"*" :: "[type, type] => type" ("(_ \<times>/ _)" [21, 20] 20)
local
subsubsection {* Definitions *}
global
consts
fst :: "'a * 'b => 'a"
snd :: "'a * 'b => 'b"
split :: "[['a, 'b] => 'c, 'a * 'b] => 'c"
curry :: "['a * 'b => 'c, 'a, 'b] => 'c"
prod_fun :: "['a => 'b, 'c => 'd, 'a * 'c] => 'b * 'd"
Pair :: "['a, 'b] => 'a * 'b"
Sigma :: "['a set, 'a => 'b set] => ('a * 'b) set"
local
defs
Pair_def: "Pair a b == Abs_Prod (Pair_Rep a b)"
fst_def: "fst p == THE a. EX b. p = Pair a b"
snd_def: "snd p == THE b. EX a. p = Pair a b"
split_def: "split == (%c p. c (fst p) (snd p))"
curry_def: "curry == (%c x y. c (Pair x y))"
prod_fun_def: "prod_fun f g == split (%x y. Pair (f x) (g y))"
Sigma_def [code func]: "Sigma A B == UN x:A. UN y:B x. {Pair x y}"
abbreviation
Times :: "['a set, 'b set] => ('a * 'b) set"
(infixr "<*>" 80) where
"A <*> B == Sigma A (%_. B)"
notation (xsymbols)
Times (infixr "\<times>" 80)
notation (HTML output)
Times (infixr "\<times>" 80)
subsubsection {* Concrete syntax *}
text {*
Patterns -- extends pre-defined type @{typ pttrn} used in
abstractions.
*}
nonterminals
tuple_args patterns
syntax
"_tuple" :: "'a => tuple_args => 'a * 'b" ("(1'(_,/ _'))")
"_tuple_arg" :: "'a => tuple_args" ("_")
"_tuple_args" :: "'a => tuple_args => tuple_args" ("_,/ _")
"_pattern" :: "[pttrn, patterns] => pttrn" ("'(_,/ _')")
"" :: "pttrn => patterns" ("_")
"_patterns" :: "[pttrn, patterns] => patterns" ("_,/ _")
"@Sigma" ::"[pttrn, 'a set, 'b set] => ('a * 'b) set" ("(3SIGMA _:_./ _)" [0, 0, 10] 10)
translations
"(x, y)" == "Pair x y"
"_tuple x (_tuple_args y z)" == "_tuple x (_tuple_arg (_tuple y z))"
"%(x,y,zs).b" == "split(%x (y,zs).b)"
"%(x,y).b" == "split(%x y. b)"
"_abs (Pair x y) t" => "%(x,y).t"
(* The last rule accommodates tuples in `case C ... (x,y) ... => ...'
The (x,y) is parsed as `Pair x y' because it is logic, not pttrn *)
"SIGMA x:A. B" == "Sigma A (%x. B)"
(* reconstructs pattern from (nested) splits, avoiding eta-contraction of body*)
(* works best with enclosing "let", if "let" does not avoid eta-contraction *)
print_translation {*
let fun split_tr' [Abs (x,T,t as (Abs abs))] =
(* split (%x y. t) => %(x,y) t *)
let val (y,t') = atomic_abs_tr' abs;
val (x',t'') = atomic_abs_tr' (x,T,t');
in Syntax.const "_abs" $ (Syntax.const "_pattern" $x'$y) $ t'' end
| split_tr' [Abs (x,T,(s as Const ("split",_)$t))] =
(* split (%x. (split (%y z. t))) => %(x,y,z). t *)
let val (Const ("_abs",_)$(Const ("_pattern",_)$y$z)$t') = split_tr' [t];
val (x',t'') = atomic_abs_tr' (x,T,t');
in Syntax.const "_abs"$
(Syntax.const "_pattern"$x'$(Syntax.const "_patterns"$y$z))$t'' end
| split_tr' [Const ("split",_)$t] =
(* split (split (%x y z. t)) => %((x,y),z). t *)
split_tr' [(split_tr' [t])] (* inner split_tr' creates next pattern *)
| split_tr' [Const ("_abs",_)$x_y$(Abs abs)] =
(* split (%pttrn z. t) => %(pttrn,z). t *)
let val (z,t) = atomic_abs_tr' abs;
in Syntax.const "_abs" $ (Syntax.const "_pattern" $x_y$z) $ t end
| split_tr' _ = raise Match;
in [("split", split_tr')]
end
*}
(* print "split f" as "\<lambda>(x,y). f x y" and "split (\<lambda>x. f x)" as "\<lambda>(x,y). f x y" *)
typed_print_translation {*
let
fun split_guess_names_tr' _ T [Abs (x,_,Abs _)] = raise Match
| split_guess_names_tr' _ T [Abs (x,xT,t)] =
(case (head_of t) of
Const ("split",_) => raise Match
| _ => let
val (_::yT::_) = binder_types (domain_type T) handle Bind => raise Match;
val (y,t') = atomic_abs_tr' ("y",yT,(incr_boundvars 1 t)$Bound 0);
val (x',t'') = atomic_abs_tr' (x,xT,t');
in Syntax.const "_abs" $ (Syntax.const "_pattern" $x'$y) $ t'' end)
| split_guess_names_tr' _ T [t] =
(case (head_of t) of
Const ("split",_) => raise Match
| _ => let
val (xT::yT::_) = binder_types (domain_type T) handle Bind => raise Match;
val (y,t') =
atomic_abs_tr' ("y",yT,(incr_boundvars 2 t)$Bound 1$Bound 0);
val (x',t'') = atomic_abs_tr' ("x",xT,t');
in Syntax.const "_abs" $ (Syntax.const "_pattern" $x'$y) $ t'' end)
| split_guess_names_tr' _ _ _ = raise Match;
in [("split", split_guess_names_tr')]
end
*}
subsubsection {* Lemmas and proof tool setup *}
lemma ProdI: "Pair_Rep a b : Prod"
unfolding Prod_def by blast
lemma Pair_Rep_inject: "Pair_Rep a b = Pair_Rep a' b' ==> a = a' & b = b'"
apply (unfold Pair_Rep_def)
apply (drule fun_cong [THEN fun_cong], blast)
done
lemma inj_on_Abs_Prod: "inj_on Abs_Prod Prod"
apply (rule inj_on_inverseI)
apply (erule Abs_Prod_inverse)
done
lemma Pair_inject:
assumes "(a, b) = (a', b')"
and "a = a' ==> b = b' ==> R"
shows R
apply (insert prems [unfolded Pair_def])
apply (rule inj_on_Abs_Prod [THEN inj_onD, THEN Pair_Rep_inject, THEN conjE])
apply (assumption | rule ProdI)+
done
lemma Pair_eq [iff]: "((a, b) = (a', b')) = (a = a' & b = b')"
by (blast elim!: Pair_inject)
lemma fst_conv [simp, code]: "fst (a, b) = a"
unfolding fst_def by blast
lemma snd_conv [simp, code]: "snd (a, b) = b"
unfolding snd_def by blast
lemma fst_eqD: "fst (x, y) = a ==> x = a"
by simp
lemma snd_eqD: "snd (x, y) = a ==> y = a"
by simp
lemma PairE_lemma: "EX x y. p = (x, y)"
apply (unfold Pair_def)
apply (rule Rep_Prod [unfolded Prod_def, THEN CollectE])
apply (erule exE, erule exE, rule exI, rule exI)
apply (rule Rep_Prod_inverse [symmetric, THEN trans])
apply (erule arg_cong)
done
lemma PairE [cases type: *]: "(!!x y. p = (x, y) ==> Q) ==> Q"
using PairE_lemma [of p] by blast
ML {*
local val PairE = thm "PairE" in
fun pair_tac s =
EVERY' [res_inst_tac [("p", s)] PairE, hyp_subst_tac, K prune_params_tac];
end;
*}
lemma surjective_pairing: "p = (fst p, snd p)"
-- {* Do not add as rewrite rule: invalidates some proofs in IMP *}
by (cases p) simp
lemmas pair_collapse = surjective_pairing [symmetric]
declare pair_collapse [simp]
lemma surj_pair [simp]: "EX x y. z = (x, y)"
apply (rule exI)
apply (rule exI)
apply (rule surjective_pairing)
done
lemma split_paired_all: "(!!x. PROP P x) == (!!a b. PROP P (a, b))"
proof
fix a b
assume "!!x. PROP P x"
then show "PROP P (a, b)" .
next
fix x
assume "!!a b. PROP P (a, b)"
from `PROP P (fst x, snd x)` show "PROP P x" by simp
qed
lemmas split_tupled_all = split_paired_all unit_all_eq2
text {*
The rule @{thm [source] split_paired_all} does not work with the
Simplifier because it also affects premises in congrence rules,
where this can lead to premises of the form @{text "!!a b. ... =
?P(a, b)"} which cannot be solved by reflexivity.
*}
ML_setup {*
(* replace parameters of product type by individual component parameters *)
val safe_full_simp_tac = generic_simp_tac true (true, false, false);
local (* filtering with exists_paired_all is an essential optimization *)
fun exists_paired_all (Const ("all", _) $ Abs (_, T, t)) =
can HOLogic.dest_prodT T orelse exists_paired_all t
| exists_paired_all (t $ u) = exists_paired_all t orelse exists_paired_all u
| exists_paired_all (Abs (_, _, t)) = exists_paired_all t
| exists_paired_all _ = false;
val ss = HOL_basic_ss
addsimps [thm "split_paired_all", thm "unit_all_eq2", thm "unit_abs_eta_conv"]
addsimprocs [unit_eq_proc];
in
val split_all_tac = SUBGOAL (fn (t, i) =>
if exists_paired_all t then safe_full_simp_tac ss i else no_tac);
val unsafe_split_all_tac = SUBGOAL (fn (t, i) =>
if exists_paired_all t then full_simp_tac ss i else no_tac);
fun split_all th =
if exists_paired_all (#prop (Thm.rep_thm th)) then full_simplify ss th else th;
end;
change_claset (fn cs => cs addSbefore ("split_all_tac", split_all_tac));
*}
lemma split_paired_All [simp]: "(ALL x. P x) = (ALL a b. P (a, b))"
-- {* @{text "[iff]"} is not a good idea because it makes @{text blast} loop *}
by fast
lemma curry_split [simp]: "curry (split f) = f"
by (simp add: curry_def split_def)
lemma split_curry [simp]: "split (curry f) = f"
by (simp add: curry_def split_def)
lemma curryI [intro!]: "f (a,b) ==> curry f a b"
by (simp add: curry_def)
lemma curryD [dest!]: "curry f a b ==> f (a,b)"
by (simp add: curry_def)
lemma curryE: "[| curry f a b ; f (a,b) ==> Q |] ==> Q"
by (simp add: curry_def)
lemma curry_conv [simp, code func]: "curry f a b = f (a,b)"
by (simp add: curry_def)
lemma prod_induct [induct type: *]: "!!x. (!!a b. P (a, b)) ==> P x"
by fast
rep_datatype prod
inject Pair_eq
induction prod_induct
lemma split_paired_Ex [simp]: "(EX x. P x) = (EX a b. P (a, b))"
by fast
lemma split_conv [simp, code func]: "split c (a, b) = c a b"
by (simp add: split_def)
lemmas split = split_conv -- {* for backwards compatibility *}
lemmas splitI = split_conv [THEN iffD2, standard]
lemmas splitD = split_conv [THEN iffD1, standard]
lemma split_Pair_apply: "split (%x y. f (x, y)) = f"
-- {* Subsumes the old @{text split_Pair} when @{term f} is the identity function. *}
apply (rule ext)
apply (tactic {* pair_tac "x" 1 *}, simp)
done
lemma split_paired_The: "(THE x. P x) = (THE (a, b). P (a, b))"
-- {* Can't be added to simpset: loops! *}
by (simp add: split_Pair_apply)
lemma The_split: "The (split P) = (THE xy. P (fst xy) (snd xy))"
by (simp add: split_def)
lemma Pair_fst_snd_eq: "!!s t. (s = t) = (fst s = fst t & snd s = snd t)"
by (simp only: split_tupled_all, simp)
lemma prod_eqI [intro?]: "fst p = fst q ==> snd p = snd q ==> p = q"
by (simp add: Pair_fst_snd_eq)
lemma split_weak_cong: "p = q ==> split c p = split c q"
-- {* Prevents simplification of @{term c}: much faster *}
by (erule arg_cong)
lemma split_eta: "(%(x, y). f (x, y)) = f"
apply (rule ext)
apply (simp only: split_tupled_all)
apply (rule split_conv)
done
lemma cond_split_eta: "(!!x y. f x y = g (x, y)) ==> (%(x, y). f x y) = g"
by (simp add: split_eta)
text {*
Simplification procedure for @{thm [source] cond_split_eta}. Using
@{thm [source] split_eta} as a rewrite rule is not general enough,
and using @{thm [source] cond_split_eta} directly would render some
existing proofs very inefficient; similarly for @{text
split_beta}. *}
ML_setup {*
local
val cond_split_eta_ss = HOL_basic_ss addsimps [thm "cond_split_eta"]
fun Pair_pat k 0 (Bound m) = (m = k)
| Pair_pat k i (Const ("Pair", _) $ Bound m $ t) = i > 0 andalso
m = k+i andalso Pair_pat k (i-1) t
| Pair_pat _ _ _ = false;
fun no_args k i (Abs (_, _, t)) = no_args (k+1) i t
| no_args k i (t $ u) = no_args k i t andalso no_args k i u
| no_args k i (Bound m) = m < k orelse m > k+i
| no_args _ _ _ = true;
fun split_pat tp i (Abs (_,_,t)) = if tp 0 i t then SOME (i,t) else NONE
| split_pat tp i (Const ("split", _) $ Abs (_, _, t)) = split_pat tp (i+1) t
| split_pat tp i _ = NONE;
fun metaeq ss lhs rhs = mk_meta_eq (Goal.prove (Simplifier.the_context ss) [] []
(HOLogic.mk_Trueprop (HOLogic.mk_eq (lhs,rhs)))
(K (simp_tac (Simplifier.inherit_context ss cond_split_eta_ss) 1)));
fun beta_term_pat k i (Abs (_, _, t)) = beta_term_pat (k+1) i t
| beta_term_pat k i (t $ u) = Pair_pat k i (t $ u) orelse
(beta_term_pat k i t andalso beta_term_pat k i u)
| beta_term_pat k i t = no_args k i t;
fun eta_term_pat k i (f $ arg) = no_args k i f andalso Pair_pat k i arg
| eta_term_pat _ _ _ = false;
fun subst arg k i (Abs (x, T, t)) = Abs (x, T, subst arg (k+1) i t)
| subst arg k i (t $ u) = if Pair_pat k i (t $ u) then incr_boundvars k arg
else (subst arg k i t $ subst arg k i u)
| subst arg k i t = t;
fun beta_proc ss (s as Const ("split", _) $ Abs (_, _, t) $ arg) =
(case split_pat beta_term_pat 1 t of
SOME (i,f) => SOME (metaeq ss s (subst arg 0 i f))
| NONE => NONE)
| beta_proc _ _ = NONE;
fun eta_proc ss (s as Const ("split", _) $ Abs (_, _, t)) =
(case split_pat eta_term_pat 1 t of
SOME (_,ft) => SOME (metaeq ss s (let val (f $ arg) = ft in f end))
| NONE => NONE)
| eta_proc _ _ = NONE;
in
val split_beta_proc = Simplifier.simproc @{theory} "split_beta" ["split f z"] (K beta_proc);
val split_eta_proc = Simplifier.simproc @{theory} "split_eta" ["split f"] (K eta_proc);
end;
Addsimprocs [split_beta_proc, split_eta_proc];
*}
lemma split_beta: "(%(x, y). P x y) z = P (fst z) (snd z)"
by (subst surjective_pairing, rule split_conv)
lemma split_split [noatp]: "R(split c p) = (ALL x y. p = (x, y) --> R(c x y))"
-- {* For use with @{text split} and the Simplifier. *}
by (insert surj_pair [of p], clarify, simp)
text {*
@{thm [source] split_split} could be declared as @{text "[split]"}
done after the Splitter has been speeded up significantly;
precompute the constants involved and don't do anything unless the
current goal contains one of those constants.
*}
lemma split_split_asm [noatp]: "R (split c p) = (~(EX x y. p = (x, y) & (~R (c x y))))"
by (subst split_split, simp)
text {*
\medskip @{term split} used as a logical connective or set former.
\medskip These rules are for use with @{text blast}; could instead
call @{text simp} using @{thm [source] split} as rewrite. *}
lemma splitI2: "!!p. [| !!a b. p = (a, b) ==> c a b |] ==> split c p"
apply (simp only: split_tupled_all)
apply (simp (no_asm_simp))
done
lemma splitI2': "!!p. [| !!a b. (a, b) = p ==> c a b x |] ==> split c p x"
apply (simp only: split_tupled_all)
apply (simp (no_asm_simp))
done
lemma splitE: "split c p ==> (!!x y. p = (x, y) ==> c x y ==> Q) ==> Q"
by (induct p) (auto simp add: split_def)
lemma splitE': "split c p z ==> (!!x y. p = (x, y) ==> c x y z ==> Q) ==> Q"
by (induct p) (auto simp add: split_def)
lemma splitE2:
"[| Q (split P z); !!x y. [|z = (x, y); Q (P x y)|] ==> R |] ==> R"
proof -
assume q: "Q (split P z)"
assume r: "!!x y. [|z = (x, y); Q (P x y)|] ==> R"
show R
apply (rule r surjective_pairing)+
apply (rule split_beta [THEN subst], rule q)
done
qed
lemma splitD': "split R (a,b) c ==> R a b c"
by simp
lemma mem_splitI: "z: c a b ==> z: split c (a, b)"
by simp
lemma mem_splitI2: "!!p. [| !!a b. p = (a, b) ==> z: c a b |] ==> z: split c p"
by (simp only: split_tupled_all, simp)
lemma mem_splitE:
assumes major: "z: split c p"
and cases: "!!x y. [| p = (x,y); z: c x y |] ==> Q"
shows Q
by (rule major [unfolded split_def] cases surjective_pairing)+
declare mem_splitI2 [intro!] mem_splitI [intro!] splitI2' [intro!] splitI2 [intro!] splitI [intro!]
declare mem_splitE [elim!] splitE' [elim!] splitE [elim!]
ML_setup {*
local (* filtering with exists_p_split is an essential optimization *)
fun exists_p_split (Const ("split",_) $ _ $ (Const ("Pair",_)$_$_)) = true
| exists_p_split (t $ u) = exists_p_split t orelse exists_p_split u
| exists_p_split (Abs (_, _, t)) = exists_p_split t
| exists_p_split _ = false;
val ss = HOL_basic_ss addsimps [thm "split_conv"];
in
val split_conv_tac = SUBGOAL (fn (t, i) =>
if exists_p_split t then safe_full_simp_tac ss i else no_tac);
end;
(* This prevents applications of splitE for already splitted arguments leading
to quite time-consuming computations (in particular for nested tuples) *)
change_claset (fn cs => cs addSbefore ("split_conv_tac", split_conv_tac));
*}
lemma split_eta_SetCompr [simp,noatp]: "(%u. EX x y. u = (x, y) & P (x, y)) = P"
by (rule ext) fast
lemma split_eta_SetCompr2 [simp,noatp]: "(%u. EX x y. u = (x, y) & P x y) = split P"
by (rule ext) fast
lemma split_part [simp]: "(%(a,b). P & Q a b) = (%ab. P & split Q ab)"
-- {* Allows simplifications of nested splits in case of independent predicates. *}
by (rule ext) blast
(* Do NOT make this a simp rule as it
a) only helps in special situations
b) can lead to nontermination in the presence of split_def
*)
lemma split_comp_eq:
fixes f :: "'a => 'b => 'c" and g :: "'d => 'a"
shows "(%u. f (g (fst u)) (snd u)) = (split (%x. f (g x)))"
by (rule ext) auto
lemma The_split_eq [simp]: "(THE (x',y'). x = x' & y = y') = (x, y)"
by blast
(*
the following would be slightly more general,
but cannot be used as rewrite rule:
### Cannot add premise as rewrite rule because it contains (type) unknowns:
### ?y = .x
Goal "[| P y; !!x. P x ==> x = y |] ==> (@(x',y). x = x' & P y) = (x,y)"
by (rtac some_equality 1)
by ( Simp_tac 1)
by (split_all_tac 1)
by (Asm_full_simp_tac 1)
qed "The_split_eq";
*)
lemma injective_fst_snd: "!!x y. [|fst x = fst y; snd x = snd y|] ==> x = y"
by auto
text {*
\bigskip @{term prod_fun} --- action of the product functor upon
functions.
*}
lemma prod_fun [simp, code func]: "prod_fun f g (a, b) = (f a, g b)"
by (simp add: prod_fun_def)
lemma prod_fun_compose: "prod_fun (f1 o f2) (g1 o g2) = (prod_fun f1 g1 o prod_fun f2 g2)"
apply (rule ext)
apply (tactic {* pair_tac "x" 1 *}, simp)
done
lemma prod_fun_ident [simp]: "prod_fun (%x. x) (%y. y) = (%z. z)"
apply (rule ext)
apply (tactic {* pair_tac "z" 1 *}, simp)
done
lemma prod_fun_imageI [intro]: "(a, b) : r ==> (f a, g b) : prod_fun f g ` r"
apply (rule image_eqI)
apply (rule prod_fun [symmetric], assumption)
done
lemma prod_fun_imageE [elim!]:
assumes major: "c: (prod_fun f g)`r"
and cases: "!!x y. [| c=(f(x),g(y)); (x,y):r |] ==> P"
shows P
apply (rule major [THEN imageE])
apply (rule_tac p = x in PairE)
apply (rule cases)
apply (blast intro: prod_fun)
apply blast
done
definition
upd_fst :: "('a \<Rightarrow> 'c) \<Rightarrow> 'a \<times> 'b \<Rightarrow> 'c \<times> 'b"
where
[code func del]: "upd_fst f = prod_fun f id"
definition
upd_snd :: "('b \<Rightarrow> 'c) \<Rightarrow> 'a \<times> 'b \<Rightarrow> 'a \<times> 'c"
where
[code func del]: "upd_snd f = prod_fun id f"
lemma upd_fst_conv [simp, code]:
"upd_fst f (x, y) = (f x, y)"
by (simp add: upd_fst_def)
lemma upd_snd_conv [simp, code]:
"upd_snd f (x, y) = (x, f y)"
by (simp add: upd_snd_def)
text {*
\bigskip Disjoint union of a family of sets -- Sigma.
*}
lemma SigmaI [intro!]: "[| a:A; b:B(a) |] ==> (a,b) : Sigma A B"
by (unfold Sigma_def) blast
lemma SigmaE [elim!]:
"[| c: Sigma A B;
!!x y.[| x:A; y:B(x); c=(x,y) |] ==> P
|] ==> P"
-- {* The general elimination rule. *}
by (unfold Sigma_def) blast
text {*
Elimination of @{term "(a, b) : A \<times> B"} -- introduces no
eigenvariables.
*}
lemma SigmaD1: "(a, b) : Sigma A B ==> a : A"
by blast
lemma SigmaD2: "(a, b) : Sigma A B ==> b : B a"
by blast
lemma SigmaE2:
"[| (a, b) : Sigma A B;
[| a:A; b:B(a) |] ==> P
|] ==> P"
by blast
lemma Sigma_cong:
"\<lbrakk>A = B; !!x. x \<in> B \<Longrightarrow> C x = D x\<rbrakk>
\<Longrightarrow> (SIGMA x: A. C x) = (SIGMA x: B. D x)"
by auto
lemma Sigma_mono: "[| A <= C; !!x. x:A ==> B x <= D x |] ==> Sigma A B <= Sigma C D"
by blast
lemma Sigma_empty1 [simp]: "Sigma {} B = {}"
by blast
lemma Sigma_empty2 [simp]: "A <*> {} = {}"
by blast
lemma UNIV_Times_UNIV [simp]: "UNIV <*> UNIV = UNIV"
by auto
lemma Compl_Times_UNIV1 [simp]: "- (UNIV <*> A) = UNIV <*> (-A)"
by auto
lemma Compl_Times_UNIV2 [simp]: "- (A <*> UNIV) = (-A) <*> UNIV"
by auto
lemma mem_Sigma_iff [iff]: "((a,b): Sigma A B) = (a:A & b:B(a))"
by blast
lemma Times_subset_cancel2: "x:C ==> (A <*> C <= B <*> C) = (A <= B)"
by blast
lemma Times_eq_cancel2: "x:C ==> (A <*> C = B <*> C) = (A = B)"
by (blast elim: equalityE)
lemma SetCompr_Sigma_eq:
"Collect (split (%x y. P x & Q x y)) = (SIGMA x:Collect P. Collect (Q x))"
by blast
text {*
\bigskip Complex rules for Sigma.
*}
lemma Collect_split [simp]: "{(a,b). P a & Q b} = Collect P <*> Collect Q"
by blast
lemma UN_Times_distrib:
"(UN (a,b):(A <*> B). E a <*> F b) = (UNION A E) <*> (UNION B F)"
-- {* Suggested by Pierre Chartier *}
by blast
lemma split_paired_Ball_Sigma [simp,noatp]:
"(ALL z: Sigma A B. P z) = (ALL x:A. ALL y: B x. P(x,y))"
by blast
lemma split_paired_Bex_Sigma [simp,noatp]:
"(EX z: Sigma A B. P z) = (EX x:A. EX y: B x. P(x,y))"
by blast
lemma Sigma_Un_distrib1: "(SIGMA i:I Un J. C(i)) = (SIGMA i:I. C(i)) Un (SIGMA j:J. C(j))"
by blast
lemma Sigma_Un_distrib2: "(SIGMA i:I. A(i) Un B(i)) = (SIGMA i:I. A(i)) Un (SIGMA i:I. B(i))"
by blast
lemma Sigma_Int_distrib1: "(SIGMA i:I Int J. C(i)) = (SIGMA i:I. C(i)) Int (SIGMA j:J. C(j))"
by blast
lemma Sigma_Int_distrib2: "(SIGMA i:I. A(i) Int B(i)) = (SIGMA i:I. A(i)) Int (SIGMA i:I. B(i))"
by blast
lemma Sigma_Diff_distrib1: "(SIGMA i:I - J. C(i)) = (SIGMA i:I. C(i)) - (SIGMA j:J. C(j))"
by blast
lemma Sigma_Diff_distrib2: "(SIGMA i:I. A(i) - B(i)) = (SIGMA i:I. A(i)) - (SIGMA i:I. B(i))"
by blast
lemma Sigma_Union: "Sigma (Union X) B = (UN A:X. Sigma A B)"
by blast
text {*
Non-dependent versions are needed to avoid the need for higher-order
matching, especially when the rules are re-oriented.
*}
lemma Times_Un_distrib1: "(A Un B) <*> C = (A <*> C) Un (B <*> C)"
by blast
lemma Times_Int_distrib1: "(A Int B) <*> C = (A <*> C) Int (B <*> C)"
by blast
lemma Times_Diff_distrib1: "(A - B) <*> C = (A <*> C) - (B <*> C)"
by blast
lemma pair_imageI [intro]: "(a, b) : A ==> f a b : (%(a, b). f a b) ` A"
apply (rule_tac x = "(a, b)" in image_eqI)
apply auto
done
text {*
Setup of internal @{text split_rule}.
*}
definition
internal_split :: "('a \<Rightarrow> 'b \<Rightarrow> 'c) \<Rightarrow> 'a \<times> 'b \<Rightarrow> 'c"
where
"internal_split == split"
lemma internal_split_conv: "internal_split c (a, b) = c a b"
by (simp only: internal_split_def split_conv)
hide const internal_split
use "Tools/split_rule.ML"
setup SplitRule.setup
lemmas prod_caseI = prod.cases [THEN iffD2, standard]
lemma prod_caseI2: "!!p. [| !!a b. p = (a, b) ==> c a b |] ==> prod_case c p"
by auto
lemma prod_caseI2': "!!p. [| !!a b. (a, b) = p ==> c a b x |] ==> prod_case c p x"
by (auto simp: split_tupled_all)
lemma prod_caseE: "prod_case c p ==> (!!x y. p = (x, y) ==> c x y ==> Q) ==> Q"
by (induct p) auto
lemma prod_caseE': "prod_case c p z ==> (!!x y. p = (x, y) ==> c x y z ==> Q) ==> Q"
by (induct p) auto
lemma prod_case_unfold: "prod_case = (%c p. c (fst p) (snd p))"
by (simp add: expand_fun_eq)
declare prod_caseI2' [intro!] prod_caseI2 [intro!] prod_caseI [intro!]
declare prod_caseE' [elim!] prod_caseE [elim!]
lemma prod_case_split:
"prod_case = split"
by (auto simp add: expand_fun_eq)
subsection {* Further cases/induct rules for tuples *}
lemma prod_cases3 [cases type]:
obtains (fields) a b c where "y = (a, b, c)"
by (cases y, case_tac b) blast
lemma prod_induct3 [case_names fields, induct type]:
"(!!a b c. P (a, b, c)) ==> P x"
by (cases x) blast
lemma prod_cases4 [cases type]:
obtains (fields) a b c d where "y = (a, b, c, d)"
by (cases y, case_tac c) blast
lemma prod_induct4 [case_names fields, induct type]:
"(!!a b c d. P (a, b, c, d)) ==> P x"
by (cases x) blast
lemma prod_cases5 [cases type]:
obtains (fields) a b c d e where "y = (a, b, c, d, e)"
by (cases y, case_tac d) blast
lemma prod_induct5 [case_names fields, induct type]:
"(!!a b c d e. P (a, b, c, d, e)) ==> P x"
by (cases x) blast
lemma prod_cases6 [cases type]:
obtains (fields) a b c d e f where "y = (a, b, c, d, e, f)"
by (cases y, case_tac e) blast
lemma prod_induct6 [case_names fields, induct type]:
"(!!a b c d e f. P (a, b, c, d, e, f)) ==> P x"
by (cases x) blast
lemma prod_cases7 [cases type]:
obtains (fields) a b c d e f g where "y = (a, b, c, d, e, f, g)"
by (cases y, case_tac f) blast
lemma prod_induct7 [case_names fields, induct type]:
"(!!a b c d e f g. P (a, b, c, d, e, f, g)) ==> P x"
by (cases x) blast
subsection {* Further lemmas *}
lemma
split_Pair: "split Pair x = x"
unfolding split_def by auto
lemma
split_comp: "split (f \<circ> g) x = f (g (fst x)) (snd x)"
by (cases x, simp)
subsection {* Code generator setup *}
instance unit :: eq ..
lemma [code func]:
"(u\<Colon>unit) = v \<longleftrightarrow> True" unfolding unit_eq [of u] unit_eq [of v] by rule+
code_type unit
(SML "unit")
(OCaml "unit")
(Haskell "()")
code_instance unit :: eq
(Haskell -)
code_const "op = \<Colon> unit \<Rightarrow> unit \<Rightarrow> bool"
(Haskell infixl 4 "==")
code_const Unity
(SML "()")
(OCaml "()")
(Haskell "()")
code_reserved SML
unit
code_reserved OCaml
unit
instance * :: (eq, eq) eq ..
lemma [code func]:
"(x1\<Colon>'a\<Colon>eq, y1\<Colon>'b\<Colon>eq) = (x2, y2) \<longleftrightarrow> x1 = x2 \<and> y1 = y2" by auto
lemma split_case_cert:
assumes "CASE \<equiv> split f"
shows "CASE (a, b) \<equiv> f a b"
using assms by simp
setup {*
Code.add_case @{thm split_case_cert}
*}
code_type *
(SML infix 2 "*")
(OCaml infix 2 "*")
(Haskell "!((_),/ (_))")
code_instance * :: eq
(Haskell -)
code_const "op = \<Colon> 'a\<Colon>eq \<times> 'b\<Colon>eq \<Rightarrow> 'a \<times> 'b \<Rightarrow> bool"
(Haskell infixl 4 "==")
code_const Pair
(SML "!((_),/ (_))")
(OCaml "!((_),/ (_))")
(Haskell "!((_),/ (_))")
code_const fst and snd
(Haskell "fst" and "snd")
types_code
"*" ("(_ */ _)")
attach (term_of) {*
fun term_of_id_42 f T g U (x, y) = HOLogic.pair_const T U $ f x $ g y;
*}
attach (test) {*
fun gen_id_42 aG bG i = (aG i, bG i);
*}
consts_code
"Pair" ("(_,/ _)")
setup {*
let
fun strip_abs_split 0 t = ([], t)
| strip_abs_split i (Abs (s, T, t)) =
let
val s' = Codegen.new_name t s;
val v = Free (s', T)
in apfst (cons v) (strip_abs_split (i-1) (subst_bound (v, t))) end
| strip_abs_split i (u as Const ("split", _) $ t) = (case strip_abs_split (i+1) t of
(v :: v' :: vs, u) => (HOLogic.mk_prod (v, v') :: vs, u)
| _ => ([], u))
| strip_abs_split i t = ([], t);
fun let_codegen thy defs gr dep thyname brack t = (case strip_comb t of
(t1 as Const ("Let", _), t2 :: t3 :: ts) =>
let
fun dest_let (l as Const ("Let", _) $ t $ u) =
(case strip_abs_split 1 u of
([p], u') => apfst (cons (p, t)) (dest_let u')
| _ => ([], l))
| dest_let t = ([], t);
fun mk_code (gr, (l, r)) =
let
val (gr1, pl) = Codegen.invoke_codegen thy defs dep thyname false (gr, l);
val (gr2, pr) = Codegen.invoke_codegen thy defs dep thyname false (gr1, r);
in (gr2, (pl, pr)) end
in case dest_let (t1 $ t2 $ t3) of
([], _) => NONE
| (ps, u) =>
let
val (gr1, qs) = foldl_map mk_code (gr, ps);
val (gr2, pu) = Codegen.invoke_codegen thy defs dep thyname false (gr1, u);
val (gr3, pargs) = foldl_map
(Codegen.invoke_codegen thy defs dep thyname true) (gr2, ts)
in
SOME (gr3, Codegen.mk_app brack
(Pretty.blk (0, [Pretty.str "let ", Pretty.blk (0, List.concat
(separate [Pretty.str ";", Pretty.brk 1] (map (fn (pl, pr) =>
[Pretty.block [Pretty.str "val ", pl, Pretty.str " =",
Pretty.brk 1, pr]]) qs))),
Pretty.brk 1, Pretty.str "in ", pu,
Pretty.brk 1, Pretty.str "end"])) pargs)
end
end
| _ => NONE);
fun split_codegen thy defs gr dep thyname brack t = (case strip_comb t of
(t1 as Const ("split", _), t2 :: ts) =>
(case strip_abs_split 1 (t1 $ t2) of
([p], u) =>
let
val (gr1, q) = Codegen.invoke_codegen thy defs dep thyname false (gr, p);
val (gr2, pu) = Codegen.invoke_codegen thy defs dep thyname false (gr1, u);
val (gr3, pargs) = foldl_map
(Codegen.invoke_codegen thy defs dep thyname true) (gr2, ts)
in
SOME (gr2, Codegen.mk_app brack
(Pretty.block [Pretty.str "(fn ", q, Pretty.str " =>",
Pretty.brk 1, pu, Pretty.str ")"]) pargs)
end
| _ => NONE)
| _ => NONE);
in
Codegen.add_codegen "let_codegen" let_codegen
#> Codegen.add_codegen "split_codegen" split_codegen
end
*}
subsection {* Legacy bindings *}
ML {*
val Collect_split = thm "Collect_split";
val Compl_Times_UNIV1 = thm "Compl_Times_UNIV1";
val Compl_Times_UNIV2 = thm "Compl_Times_UNIV2";
val PairE = thm "PairE";
val PairE_lemma = thm "PairE_lemma";
val Pair_Rep_inject = thm "Pair_Rep_inject";
val Pair_def = thm "Pair_def";
val Pair_eq = thm "Pair_eq";
val Pair_fst_snd_eq = thm "Pair_fst_snd_eq";
val Pair_inject = thm "Pair_inject";
val ProdI = thm "ProdI";
val SetCompr_Sigma_eq = thm "SetCompr_Sigma_eq";
val SigmaD1 = thm "SigmaD1";
val SigmaD2 = thm "SigmaD2";
val SigmaE = thm "SigmaE";
val SigmaE2 = thm "SigmaE2";
val SigmaI = thm "SigmaI";
val Sigma_Diff_distrib1 = thm "Sigma_Diff_distrib1";
val Sigma_Diff_distrib2 = thm "Sigma_Diff_distrib2";
val Sigma_Int_distrib1 = thm "Sigma_Int_distrib1";
val Sigma_Int_distrib2 = thm "Sigma_Int_distrib2";
val Sigma_Un_distrib1 = thm "Sigma_Un_distrib1";
val Sigma_Un_distrib2 = thm "Sigma_Un_distrib2";
val Sigma_Union = thm "Sigma_Union";
val Sigma_def = thm "Sigma_def";
val Sigma_empty1 = thm "Sigma_empty1";
val Sigma_empty2 = thm "Sigma_empty2";
val Sigma_mono = thm "Sigma_mono";
val The_split = thm "The_split";
val The_split_eq = thm "The_split_eq";
val The_split_eq = thm "The_split_eq";
val Times_Diff_distrib1 = thm "Times_Diff_distrib1";
val Times_Int_distrib1 = thm "Times_Int_distrib1";
val Times_Un_distrib1 = thm "Times_Un_distrib1";
val Times_eq_cancel2 = thm "Times_eq_cancel2";
val Times_subset_cancel2 = thm "Times_subset_cancel2";
val UNIV_Times_UNIV = thm "UNIV_Times_UNIV";
val UN_Times_distrib = thm "UN_Times_distrib";
val Unity_def = thm "Unity_def";
val cond_split_eta = thm "cond_split_eta";
val fst_conv = thm "fst_conv";
val fst_def = thm "fst_def";
val fst_eqD = thm "fst_eqD";
val inj_on_Abs_Prod = thm "inj_on_Abs_Prod";
val injective_fst_snd = thm "injective_fst_snd";
val mem_Sigma_iff = thm "mem_Sigma_iff";
val mem_splitE = thm "mem_splitE";
val mem_splitI = thm "mem_splitI";
val mem_splitI2 = thm "mem_splitI2";
val prod_eqI = thm "prod_eqI";
val prod_fun = thm "prod_fun";
val prod_fun_compose = thm "prod_fun_compose";
val prod_fun_def = thm "prod_fun_def";
val prod_fun_ident = thm "prod_fun_ident";
val prod_fun_imageE = thm "prod_fun_imageE";
val prod_fun_imageI = thm "prod_fun_imageI";
val prod_induct = thm "prod_induct";
val snd_conv = thm "snd_conv";
val snd_def = thm "snd_def";
val snd_eqD = thm "snd_eqD";
val split = thm "split";
val splitD = thm "splitD";
val splitD' = thm "splitD'";
val splitE = thm "splitE";
val splitE' = thm "splitE'";
val splitE2 = thm "splitE2";
val splitI = thm "splitI";
val splitI2 = thm "splitI2";
val splitI2' = thm "splitI2'";
val split_Pair_apply = thm "split_Pair_apply";
val split_beta = thm "split_beta";
val split_conv = thm "split_conv";
val split_def = thm "split_def";
val split_eta = thm "split_eta";
val split_eta_SetCompr = thm "split_eta_SetCompr";
val split_eta_SetCompr2 = thm "split_eta_SetCompr2";
val split_paired_All = thm "split_paired_All";
val split_paired_Ball_Sigma = thm "split_paired_Ball_Sigma";
val split_paired_Bex_Sigma = thm "split_paired_Bex_Sigma";
val split_paired_Ex = thm "split_paired_Ex";
val split_paired_The = thm "split_paired_The";
val split_paired_all = thm "split_paired_all";
val split_part = thm "split_part";
val split_split = thm "split_split";
val split_split_asm = thm "split_split_asm";
val split_tupled_all = thms "split_tupled_all";
val split_weak_cong = thm "split_weak_cong";
val surj_pair = thm "surj_pair";
val surjective_pairing = thm "surjective_pairing";
val unit_abs_eta_conv = thm "unit_abs_eta_conv";
val unit_all_eq1 = thm "unit_all_eq1";
val unit_all_eq2 = thm "unit_all_eq2";
val unit_eq = thm "unit_eq";
val unit_induct = thm "unit_induct";
*}
subsection {* Further inductive packages *}
use "Tools/inductive_realizer.ML"
setup InductiveRealizer.setup
use "Tools/inductive_set_package.ML"
setup InductiveSetPackage.setup
use "Tools/datatype_realizer.ML"
setup DatatypeRealizer.setup
end