--- a/src/HOL/UNITY/ProgressSets.thy Fri Mar 14 10:30:15 2003 +0100
+++ b/src/HOL/UNITY/ProgressSets.thy Fri Mar 14 10:30:46 2003 +0100
@@ -8,6 +8,10 @@
David Meier and Beverly Sanders,
Composing Leads-to Properties
Theoretical Computer Science 243:1-2 (2000), 339-361.
+
+ David Meier,
+ Progress Properties in Program Refinement and Parallel Composition
+ Swiss Federal Institute of Technology Zurich (1997)
*)
header{*Progress Sets*}
@@ -15,102 +19,220 @@
theory ProgressSets = Transformers:
constdefs
- closure_set :: "'a set set => bool"
- "closure_set C ==
- (\<forall>D. D \<subseteq> C --> \<Inter>D \<in> C) & (\<forall>D. D \<subseteq> C --> \<Union>D \<in> C)"
+ lattice :: "'a set set => bool"
+ --{*Meier calls them closure sets, but they are just complete lattices*}
+ "lattice L ==
+ (\<forall>M. M \<subseteq> L --> \<Inter>M \<in> L) & (\<forall>M. M \<subseteq> L --> \<Union>M \<in> L)"
cl :: "['a set set, 'a set] => 'a set"
--{*short for ``closure''*}
- "cl C r == \<Inter>{x. x\<in>C & r \<subseteq> x}"
+ "cl L r == \<Inter>{x. x\<in>L & r \<subseteq> x}"
-lemma UNIV_in_closure_set: "closure_set C ==> UNIV \<in> C"
-by (force simp add: closure_set_def)
+lemma UNIV_in_lattice: "lattice L ==> UNIV \<in> L"
+by (force simp add: lattice_def)
-lemma empty_in_closure_set: "closure_set C ==> {} \<in> C"
-by (force simp add: closure_set_def)
+lemma empty_in_lattice: "lattice L ==> {} \<in> L"
+by (force simp add: lattice_def)
-lemma Union_in_closure_set: "[|D \<subseteq> C; closure_set C|] ==> \<Union>D \<in> C"
-by (simp add: closure_set_def)
+lemma Union_in_lattice: "[|M \<subseteq> L; lattice L|] ==> \<Union>M \<in> L"
+by (simp add: lattice_def)
-lemma Inter_in_closure_set: "[|D \<subseteq> C; closure_set C|] ==> \<Inter>D \<in> C"
-by (simp add: closure_set_def)
+lemma Inter_in_lattice: "[|M \<subseteq> L; lattice L|] ==> \<Inter>M \<in> L"
+by (simp add: lattice_def)
-lemma UN_in_closure_set:
- "[|closure_set C; !!i. i\<in>I ==> r i \<in> C|] ==> (\<Union>i\<in>I. r i) \<in> C"
+lemma UN_in_lattice:
+ "[|lattice L; !!i. i\<in>I ==> r i \<in> L|] ==> (\<Union>i\<in>I. r i) \<in> L"
apply (simp add: Set.UN_eq)
-apply (blast intro: Union_in_closure_set)
+apply (blast intro: Union_in_lattice)
done
-lemma IN_in_closure_set:
- "[|closure_set C; !!i. i\<in>I ==> r i \<in> C|] ==> (\<Inter>i\<in>I. r i) \<in> C"
+lemma INT_in_lattice:
+ "[|lattice L; !!i. i\<in>I ==> r i \<in> L|] ==> (\<Inter>i\<in>I. r i) \<in> L"
apply (simp add: INT_eq)
-apply (blast intro: Inter_in_closure_set)
+apply (blast intro: Inter_in_lattice)
done
-lemma Un_in_closure_set: "[|x\<in>C; y\<in>C; closure_set C|] ==> x\<union>y \<in> C"
+lemma Un_in_lattice: "[|x\<in>L; y\<in>L; lattice L|] ==> x\<union>y \<in> L"
apply (simp only: Un_eq_Union)
-apply (blast intro: Union_in_closure_set)
+apply (blast intro: Union_in_lattice)
done
-lemma Int_in_closure_set: "[|x\<in>C; y\<in>C; closure_set C|] ==> x\<inter>y \<in> C"
+lemma Int_in_lattice: "[|x\<in>L; y\<in>L; lattice L|] ==> x\<inter>y \<in> L"
apply (simp only: Int_eq_Inter)
-apply (blast intro: Inter_in_closure_set)
+apply (blast intro: Inter_in_lattice)
done
-lemma closure_set_stable: "closure_set {X. F \<in> stable X}"
-by (simp add: closure_set_def stable_def constrains_def, blast)
+lemma lattice_stable: "lattice {X. F \<in> stable X}"
+by (simp add: lattice_def stable_def constrains_def, blast)
-text{*The next three results state that @{term "cl C r"} is the minimal
- element of @{term C} that includes @{term r}.*}
-lemma cl_in_closure_set: "closure_set C ==> cl C r \<in> C"
-apply (simp add: closure_set_def cl_def)
+text{*The next three results state that @{term "cl L r"} is the minimal
+ element of @{term L} that includes @{term r}.*}
+lemma cl_in_lattice: "lattice L ==> cl L r \<in> L"
+apply (simp add: lattice_def cl_def)
apply (erule conjE)
apply (drule spec, erule mp, blast)
done
-lemma cl_least: "[|c\<in>C; r\<subseteq>c|] ==> cl C r \<subseteq> c"
+lemma cl_least: "[|c\<in>L; r\<subseteq>c|] ==> cl L r \<subseteq> c"
by (force simp add: cl_def)
text{*The next three lemmas constitute assertion (4.61)*}
-lemma cl_mono: "r \<subseteq> r' ==> cl C r \<subseteq> cl C r'"
+lemma cl_mono: "r \<subseteq> r' ==> cl L r \<subseteq> cl L r'"
+by (simp add: cl_def, blast)
+
+lemma subset_cl: "r \<subseteq> cl L r"
+by (simp add: cl_def, blast)
+
+lemma cl_UN_subset: "(\<Union>i\<in>I. cl L (r i)) \<subseteq> cl L (\<Union>i\<in>I. r i)"
by (simp add: cl_def, blast)
-lemma subset_cl: "r \<subseteq> cl C r"
-by (simp add: cl_def, blast)
+lemma cl_Un: "lattice L ==> cl L (r\<union>s) = cl L r \<union> cl L s"
+apply (rule equalityI)
+ prefer 2
+ apply (simp add: cl_def, blast)
+apply (rule cl_least)
+ apply (blast intro: Un_in_lattice cl_in_lattice)
+apply (blast intro: subset_cl [THEN subsetD])
+done
-lemma cl_UN_subset: "(\<Union>i\<in>I. cl C (r i)) \<subseteq> cl C (\<Union>i\<in>I. r i)"
-by (simp add: cl_def, blast)
-
-lemma cl_Un: "closure_set C ==> cl C (r\<union>s) = cl C r \<union> cl C s"
+lemma cl_UN: "lattice L ==> cl L (\<Union>i\<in>I. r i) = (\<Union>i\<in>I. cl L (r i))"
apply (rule equalityI)
prefer 2
apply (simp add: cl_def, blast)
apply (rule cl_least)
- apply (blast intro: Un_in_closure_set cl_in_closure_set)
-apply (blast intro: subset_cl [THEN subsetD])
-done
-
-lemma cl_UN: "closure_set C ==> cl C (\<Union>i\<in>I. r i) = (\<Union>i\<in>I. cl C (r i))"
-apply (rule equalityI)
- prefer 2
- apply (simp add: cl_def, blast)
-apply (rule cl_least)
- apply (blast intro: UN_in_closure_set cl_in_closure_set)
+ apply (blast intro: UN_in_lattice cl_in_lattice)
apply (blast intro: subset_cl [THEN subsetD])
done
-lemma cl_idem [simp]: "cl C (cl C r) = cl C r"
+lemma cl_idem [simp]: "cl L (cl L r) = cl L r"
by (simp add: cl_def, blast)
-lemma cl_ident: "r\<in>C ==> cl C r = r"
+lemma cl_ident: "r\<in>L ==> cl L r = r"
by (force simp add: cl_def)
text{*Assertion (4.62)*}
-lemma cl_ident_iff: "closure_set C ==> (cl C r = r) = (r\<in>C)"
+lemma cl_ident_iff: "lattice L ==> (cl L r = r) = (r\<in>L)"
apply (rule iffI)
apply (erule subst)
- apply (erule cl_in_closure_set)
+ apply (erule cl_in_lattice)
apply (erule cl_ident)
done
+lemma cl_subset_in_lattice: "[|cl L r \<subseteq> r; lattice L|] ==> r\<in>L"
+by (simp add: cl_ident_iff [symmetric] equalityI subset_cl)
+
+
+constdefs
+ closed :: "['a program, 'a set, 'a set, 'a set set] => bool"
+ "closed F T B L == \<forall>M. \<forall>act \<in> Acts F. B\<subseteq>M & T\<inter>M \<in> L -->
+ T \<inter> (B \<union> wp act M) \<in> L"
+
+ progress_set :: "['a program, 'a set, 'a set] => 'a set set set"
+ "progress_set F T B ==
+ {L. F \<in> stable T & lattice L & B \<in> L & T \<in> L & closed F T B L}"
+
+lemma closedD:
+ "[|closed F T B L; act \<in> Acts F; B\<subseteq>M; T\<inter>M \<in> L|]
+ ==> T \<inter> (B \<union> wp act M) \<in> L"
+by (simp add: closed_def)
+
+lemma lattice_awp_lemma:
+ assumes tmc: "T\<inter>m \<in> C" --{*induction hypothesis in theorem below*}
+ and qsm: "q \<subseteq> m" --{*holds in inductive step*}
+ and latt: "lattice C"
+ and tc: "T \<in> C"
+ and qc: "q \<in> C"
+ and clos: "closed F T q C"
+ shows "T \<inter> (q \<union> awp F (m \<union> cl C (T\<inter>r))) \<in> C"
+apply (simp del: INT_simps add: awp_def INT_extend_simps)
+apply (rule INT_in_lattice [OF latt])
+apply (erule closedD [OF clos])
+apply (simp add: subset_trans [OF qsm Un_upper1])
+apply (subgoal_tac "T \<inter> (m \<union> cl C (T\<inter>r)) = (T\<inter>m) \<union> cl C (T\<inter>r)")
+ prefer 2 apply (blast intro: tc rev_subsetD [OF _ cl_least])
+apply (erule ssubst)
+apply (blast intro: Un_in_lattice latt cl_in_lattice tmc)
+done
+
+lemma lattice_lemma:
+ assumes tmc: "T\<inter>m \<in> C" --{*induction hypothesis in theorem below*}
+ and qsm: "q \<subseteq> m" --{*holds in inductive step*}
+ and act: "act \<in> Acts F"
+ and latt: "lattice C"
+ and tc: "T \<in> C"
+ and qc: "q \<in> C"
+ and clos: "closed F T q C"
+ shows "T \<inter> (wp act m \<inter> awp F (m \<union> cl C (T\<inter>r)) \<union> m) \<in> C"
+apply (subgoal_tac "T \<inter> (q \<union> wp act m) \<in> C")
+ prefer 2 apply (simp add: closedD [OF clos] act qsm tmc)
+apply (drule Int_in_lattice
+ [OF _ lattice_awp_lemma [OF tmc qsm latt tc qc clos, of r]
+ latt])
+apply (subgoal_tac
+ "T \<inter> (q \<union> wp act m) \<inter> (T \<inter> (q \<union> awp F (m \<union> cl C (T\<inter>r)))) =
+ T \<inter> (q \<union> wp act m \<inter> awp F (m \<union> cl C (T\<inter>r)))")
+ prefer 2 apply blast
+apply simp
+apply (drule Un_in_lattice [OF _ tmc latt])
+apply (subgoal_tac
+ "T \<inter> (q \<union> wp act m \<inter> awp F (m \<union> cl C (T\<inter>r))) \<union> T\<inter>m =
+ T \<inter> (wp act m \<inter> awp F (m \<union> cl C (T\<inter>r)) \<union> m)")
+ prefer 2 apply (blast intro: qsm [THEN subsetD], simp)
+done
+
+
+lemma progress_induction_step:
+ assumes tmc: "T\<inter>m \<in> C" --{*induction hypothesis in theorem below*}
+ and act: "act \<in> Acts F"
+ and mwens: "m \<in> wens_set F q"
+ and latt: "lattice C"
+ and tc: "T \<in> C"
+ and qc: "q \<in> C"
+ and clos: "closed F T q C"
+ and Fstable: "F \<in> stable T"
+ shows "T \<inter> wens F act m \<in> C"
+proof -
+from mwens have qsm: "q \<subseteq> m"
+ by (rule wens_set_imp_subset)
+let ?r = "wens F act m"
+have "?r \<subseteq> (wp act m \<inter> awp F (m\<union>?r)) \<union> m"
+ by (simp add: wens_unfold [symmetric])
+then have "T\<inter>?r \<subseteq> T \<inter> ((wp act m \<inter> awp F (m\<union>?r)) \<union> m)"
+ by blast
+then have "T\<inter>?r \<subseteq> T \<inter> ((wp act m \<inter> awp F (T \<inter> (m\<union>?r))) \<union> m)"
+ by (simp add: awp_Int_eq Fstable stable_imp_awp_ident, blast)
+then have "T\<inter>?r \<subseteq> T \<inter> ((wp act m \<inter> awp F (m \<union> cl C (T\<inter>?r))) \<union> m)"
+ by (blast intro: awp_mono [THEN [2] rev_subsetD] subset_cl [THEN subsetD])
+then have "cl C (T\<inter>?r) \<subseteq>
+ cl C (T \<inter> ((wp act m \<inter> awp F (m \<union> cl C (T\<inter>?r))) \<union> m))"
+ by (rule cl_mono)
+then have "cl C (T\<inter>?r) \<subseteq>
+ T \<inter> ((wp act m \<inter> awp F (m \<union> cl C (T\<inter>?r))) \<union> m)"
+ by (simp add: cl_ident lattice_lemma [OF tmc qsm act latt tc qc clos])
+then have "cl C (T\<inter>?r) \<subseteq> (wp act m \<inter> awp F (m \<union> cl C (T\<inter>?r))) \<union> m"
+ by blast
+then have "cl C (T\<inter>?r) \<subseteq> ?r"
+ by (blast intro!: subset_wens)
+then have cl_subset: "cl C (T\<inter>?r) \<subseteq> T\<inter>?r"
+ by (simp add: Int_subset_iff cl_ident tc
+ subset_trans [OF cl_mono [OF Int_lower1]])
+show ?thesis
+ by (rule cl_subset_in_lattice [OF cl_subset latt])
+qed
+
+
+lemma progress_set_lemma:
+ "[|C \<in> progress_set F T B; r \<in> wens_set F B|] ==> T\<inter>r \<in> C"
+apply (simp add: progress_set_def, clarify)
+apply (erule wens_set.induct)
+ txt{*Base*}
+ apply (simp add: Int_in_lattice)
+ txt{*The difficult @{term wens} case*}
+ apply (simp add: progress_induction_step)
+txt{*Disjunctive case*}
+apply (subgoal_tac "(\<Union>U\<in>W. T \<inter> U) \<in> C")
+ apply (simp add: Int_Union)
+apply (blast intro: UN_in_lattice)
+done
+
end