src/HOL/HOLCF/Deflation.thy
changeset 67312 0d25e02759b7
parent 65380 ae93953746fc
child 81577 a712bf5ccab0
--- a/src/HOL/HOLCF/Deflation.thy	Mon Jan 01 21:17:28 2018 +0100
+++ b/src/HOL/HOLCF/Deflation.thy	Mon Jan 01 23:07:24 2018 +0100
@@ -5,11 +5,12 @@
 section \<open>Continuous deflations and ep-pairs\<close>
 
 theory Deflation
-imports Cfun
+  imports Cfun
 begin
 
 default_sort cpo
 
+
 subsection \<open>Continuous deflations\<close>
 
 locale deflation =
@@ -19,15 +20,15 @@
 begin
 
 lemma below_ID: "d \<sqsubseteq> ID"
-by (rule cfun_belowI, simp add: below)
+  by (rule cfun_belowI) (simp add: below)
 
 text \<open>The set of fixed points is the same as the range.\<close>
 
 lemma fixes_eq_range: "{x. d\<cdot>x = x} = range (\<lambda>x. d\<cdot>x)"
-by (auto simp add: eq_sym_conv idem)
+  by (auto simp add: eq_sym_conv idem)
 
 lemma range_eq_fixes: "range (\<lambda>x. d\<cdot>x) = {x. d\<cdot>x = x}"
-by (auto simp add: eq_sym_conv idem)
+  by (auto simp add: eq_sym_conv idem)
 
 text \<open>
   The pointwise ordering on deflation functions coincides with
@@ -35,20 +36,22 @@
 \<close>
 
 lemma belowI:
-  assumes f: "\<And>x. d\<cdot>x = x \<Longrightarrow> f\<cdot>x = x" shows "d \<sqsubseteq> f"
+  assumes f: "\<And>x. d\<cdot>x = x \<Longrightarrow> f\<cdot>x = x"
+  shows "d \<sqsubseteq> f"
 proof (rule cfun_belowI)
   fix x
-  from below have "f\<cdot>(d\<cdot>x) \<sqsubseteq> f\<cdot>x" by (rule monofun_cfun_arg)
-  also from idem have "f\<cdot>(d\<cdot>x) = d\<cdot>x" by (rule f)
+  from below have "f\<cdot>(d\<cdot>x) \<sqsubseteq> f\<cdot>x"
+    by (rule monofun_cfun_arg)
+  also from idem have "f\<cdot>(d\<cdot>x) = d\<cdot>x"
+    by (rule f)
   finally show "d\<cdot>x \<sqsubseteq> f\<cdot>x" .
 qed
 
 lemma belowD: "\<lbrakk>f \<sqsubseteq> d; f\<cdot>x = x\<rbrakk> \<Longrightarrow> d\<cdot>x = x"
 proof (rule below_antisym)
   from below show "d\<cdot>x \<sqsubseteq> x" .
-next
   assume "f \<sqsubseteq> d"
-  hence "f\<cdot>x \<sqsubseteq> d\<cdot>x" by (rule monofun_cfun_fun)
+  then have "f\<cdot>x \<sqsubseteq> d\<cdot>x" by (rule monofun_cfun_fun)
   also assume "f\<cdot>x = x"
   finally show "x \<sqsubseteq> d\<cdot>x" .
 qed
@@ -56,23 +59,22 @@
 end
 
 lemma deflation_strict: "deflation d \<Longrightarrow> d\<cdot>\<bottom> = \<bottom>"
-by (rule deflation.below [THEN bottomI])
+  by (rule deflation.below [THEN bottomI])
 
 lemma adm_deflation: "adm (\<lambda>d. deflation d)"
-by (simp add: deflation_def)
+  by (simp add: deflation_def)
 
 lemma deflation_ID: "deflation ID"
-by (simp add: deflation.intro)
+  by (simp add: deflation.intro)
 
 lemma deflation_bottom: "deflation \<bottom>"
-by (simp add: deflation.intro)
+  by (simp add: deflation.intro)
 
-lemma deflation_below_iff:
-  "\<lbrakk>deflation p; deflation q\<rbrakk> \<Longrightarrow> p \<sqsubseteq> q \<longleftrightarrow> (\<forall>x. p\<cdot>x = x \<longrightarrow> q\<cdot>x = x)"
- apply safe
-  apply (simp add: deflation.belowD)
- apply (simp add: deflation.belowI)
-done
+lemma deflation_below_iff: "deflation p \<Longrightarrow> deflation q \<Longrightarrow> p \<sqsubseteq> q \<longleftrightarrow> (\<forall>x. p\<cdot>x = x \<longrightarrow> q\<cdot>x = x)"
+  apply safe
+   apply (simp add: deflation.belowD)
+  apply (simp add: deflation.belowI)
+  done
 
 text \<open>
   The composition of two deflations is equal to
@@ -88,26 +90,26 @@
   from g.below show "f\<cdot>(g\<cdot>x) \<sqsubseteq> f\<cdot>x" by (rule monofun_cfun_arg)
 next
   interpret f: deflation f by fact
-  assume "f \<sqsubseteq> g" hence "f\<cdot>x \<sqsubseteq> g\<cdot>x" by (rule monofun_cfun_fun)
-  hence "f\<cdot>(f\<cdot>x) \<sqsubseteq> f\<cdot>(g\<cdot>x)" by (rule monofun_cfun_arg)
+  assume "f \<sqsubseteq> g"
+  then have "f\<cdot>x \<sqsubseteq> g\<cdot>x" by (rule monofun_cfun_fun)
+  then have "f\<cdot>(f\<cdot>x) \<sqsubseteq> f\<cdot>(g\<cdot>x)" by (rule monofun_cfun_arg)
   also have "f\<cdot>(f\<cdot>x) = f\<cdot>x" by (rule f.idem)
   finally show "f\<cdot>x \<sqsubseteq> f\<cdot>(g\<cdot>x)" .
 qed
 
-lemma deflation_below_comp2:
-  "\<lbrakk>deflation f; deflation g; f \<sqsubseteq> g\<rbrakk> \<Longrightarrow> g\<cdot>(f\<cdot>x) = f\<cdot>x"
-by (simp only: deflation.belowD deflation.idem)
+lemma deflation_below_comp2: "deflation f \<Longrightarrow> deflation g \<Longrightarrow> f \<sqsubseteq> g \<Longrightarrow> g\<cdot>(f\<cdot>x) = f\<cdot>x"
+  by (simp only: deflation.belowD deflation.idem)
 
 
 subsection \<open>Deflations with finite range\<close>
 
 lemma finite_range_imp_finite_fixes:
-  "finite (range f) \<Longrightarrow> finite {x. f x = x}"
+  assumes "finite (range f)"
+  shows "finite {x. f x = x}"
 proof -
   have "{x. f x = x} \<subseteq> range f"
     by (clarify, erule subst, rule rangeI)
-  moreover assume "finite (range f)"
-  ultimately show "finite {x. f x = x}"
+  from this assms show "finite {x. f x = x}"
     by (rule finite_subset)
 qed
 
@@ -116,10 +118,10 @@
 begin
 
 lemma finite_range: "finite (range (\<lambda>x. d\<cdot>x))"
-by (simp add: range_eq_fixes finite_fixes)
+  by (simp add: range_eq_fixes finite_fixes)
 
 lemma finite_image: "finite ((\<lambda>x. d\<cdot>x) ` A)"
-by (rule finite_subset [OF image_mono [OF subset_UNIV] finite_range])
+  by (rule finite_subset [OF image_mono [OF subset_UNIV] finite_range])
 
 lemma compact: "compact (d\<cdot>x)"
 proof (rule compactI2)
@@ -127,41 +129,36 @@
   assume Y: "chain Y"
   have "finite_chain (\<lambda>i. d\<cdot>(Y i))"
   proof (rule finite_range_imp_finch)
-    show "chain (\<lambda>i. d\<cdot>(Y i))"
-      using Y by simp
-    have "range (\<lambda>i. d\<cdot>(Y i)) \<subseteq> range (\<lambda>x. d\<cdot>x)"
-      by clarsimp
-    thus "finite (range (\<lambda>i. d\<cdot>(Y i)))"
+    from Y show "chain (\<lambda>i. d\<cdot>(Y i))" by simp
+    have "range (\<lambda>i. d\<cdot>(Y i)) \<subseteq> range (\<lambda>x. d\<cdot>x)" by auto
+    then show "finite (range (\<lambda>i. d\<cdot>(Y i)))"
       using finite_range by (rule finite_subset)
   qed
-  hence "\<exists>j. (\<Squnion>i. d\<cdot>(Y i)) = d\<cdot>(Y j)"
+  then have "\<exists>j. (\<Squnion>i. d\<cdot>(Y i)) = d\<cdot>(Y j)"
     by (simp add: finite_chain_def maxinch_is_thelub Y)
   then obtain j where j: "(\<Squnion>i. d\<cdot>(Y i)) = d\<cdot>(Y j)" ..
 
   assume "d\<cdot>x \<sqsubseteq> (\<Squnion>i. Y i)"
-  hence "d\<cdot>(d\<cdot>x) \<sqsubseteq> d\<cdot>(\<Squnion>i. Y i)"
+  then have "d\<cdot>(d\<cdot>x) \<sqsubseteq> d\<cdot>(\<Squnion>i. Y i)"
     by (rule monofun_cfun_arg)
-  hence "d\<cdot>x \<sqsubseteq> (\<Squnion>i. d\<cdot>(Y i))"
+  then have "d\<cdot>x \<sqsubseteq> (\<Squnion>i. d\<cdot>(Y i))"
     by (simp add: contlub_cfun_arg Y idem)
-  hence "d\<cdot>x \<sqsubseteq> d\<cdot>(Y j)"
-    using j by simp
-  hence "d\<cdot>x \<sqsubseteq> Y j"
+  with j have "d\<cdot>x \<sqsubseteq> d\<cdot>(Y j)" by simp
+  then have "d\<cdot>x \<sqsubseteq> Y j"
     using below by (rule below_trans)
-  thus "\<exists>j. d\<cdot>x \<sqsubseteq> Y j" ..
+  then show "\<exists>j. d\<cdot>x \<sqsubseteq> Y j" ..
 qed
 
 end
 
-lemma finite_deflation_intro:
-  "deflation d \<Longrightarrow> finite {x. d\<cdot>x = x} \<Longrightarrow> finite_deflation d"
-by (intro finite_deflation.intro finite_deflation_axioms.intro)
+lemma finite_deflation_intro: "deflation d \<Longrightarrow> finite {x. d\<cdot>x = x} \<Longrightarrow> finite_deflation d"
+  by (intro finite_deflation.intro finite_deflation_axioms.intro)
 
-lemma finite_deflation_imp_deflation:
-  "finite_deflation d \<Longrightarrow> deflation d"
-unfolding finite_deflation_def by simp
+lemma finite_deflation_imp_deflation: "finite_deflation d \<Longrightarrow> deflation d"
+  by (simp add: finite_deflation_def)
 
 lemma finite_deflation_bottom: "finite_deflation \<bottom>"
-by standard simp_all
+  by standard simp_all
 
 
 subsection \<open>Continuous embedding-projection pairs\<close>
@@ -175,22 +172,21 @@
 lemma e_below_iff [simp]: "e\<cdot>x \<sqsubseteq> e\<cdot>y \<longleftrightarrow> x \<sqsubseteq> y"
 proof
   assume "e\<cdot>x \<sqsubseteq> e\<cdot>y"
-  hence "p\<cdot>(e\<cdot>x) \<sqsubseteq> p\<cdot>(e\<cdot>y)" by (rule monofun_cfun_arg)
-  thus "x \<sqsubseteq> y" by simp
+  then have "p\<cdot>(e\<cdot>x) \<sqsubseteq> p\<cdot>(e\<cdot>y)" by (rule monofun_cfun_arg)
+  then show "x \<sqsubseteq> y" by simp
 next
   assume "x \<sqsubseteq> y"
-  thus "e\<cdot>x \<sqsubseteq> e\<cdot>y" by (rule monofun_cfun_arg)
+  then show "e\<cdot>x \<sqsubseteq> e\<cdot>y" by (rule monofun_cfun_arg)
 qed
 
 lemma e_eq_iff [simp]: "e\<cdot>x = e\<cdot>y \<longleftrightarrow> x = y"
-unfolding po_eq_conv e_below_iff ..
+  unfolding po_eq_conv e_below_iff ..
 
-lemma p_eq_iff:
-  "\<lbrakk>e\<cdot>(p\<cdot>x) = x; e\<cdot>(p\<cdot>y) = y\<rbrakk> \<Longrightarrow> p\<cdot>x = p\<cdot>y \<longleftrightarrow> x = y"
-by (safe, erule subst, erule subst, simp)
+lemma p_eq_iff: "e\<cdot>(p\<cdot>x) = x \<Longrightarrow> e\<cdot>(p\<cdot>y) = y \<Longrightarrow> p\<cdot>x = p\<cdot>y \<longleftrightarrow> x = y"
+  by (safe, erule subst, erule subst, simp)
 
-lemma p_inverse: "(\<exists>x. y = e\<cdot>x) = (e\<cdot>(p\<cdot>y) = y)"
-by (auto, rule exI, erule sym)
+lemma p_inverse: "(\<exists>x. y = e\<cdot>x) \<longleftrightarrow> e\<cdot>(p\<cdot>y) = y"
+  by (auto, rule exI, erule sym)
 
 lemma e_below_iff_below_p: "e\<cdot>x \<sqsubseteq> y \<longleftrightarrow> x \<sqsubseteq> p\<cdot>y"
 proof
@@ -206,28 +202,29 @@
 lemma compact_e_rev: "compact (e\<cdot>x) \<Longrightarrow> compact x"
 proof -
   assume "compact (e\<cdot>x)"
-  hence "adm (\<lambda>y. e\<cdot>x \<notsqsubseteq> y)" by (rule compactD)
-  hence "adm (\<lambda>y. e\<cdot>x \<notsqsubseteq> e\<cdot>y)" by (rule adm_subst [OF cont_Rep_cfun2])
-  hence "adm (\<lambda>y. x \<notsqsubseteq> y)" by simp
-  thus "compact x" by (rule compactI)
+  then have "adm (\<lambda>y. e\<cdot>x \<notsqsubseteq> y)" by (rule compactD)
+  then have "adm (\<lambda>y. e\<cdot>x \<notsqsubseteq> e\<cdot>y)" by (rule adm_subst [OF cont_Rep_cfun2])
+  then have "adm (\<lambda>y. x \<notsqsubseteq> y)" by simp
+  then show "compact x" by (rule compactI)
 qed
 
-lemma compact_e: "compact x \<Longrightarrow> compact (e\<cdot>x)"
+lemma compact_e:
+  assumes "compact x"
+  shows "compact (e\<cdot>x)"
 proof -
-  assume "compact x"
-  hence "adm (\<lambda>y. x \<notsqsubseteq> y)" by (rule compactD)
-  hence "adm (\<lambda>y. x \<notsqsubseteq> p\<cdot>y)" by (rule adm_subst [OF cont_Rep_cfun2])
-  hence "adm (\<lambda>y. e\<cdot>x \<notsqsubseteq> y)" by (simp add: e_below_iff_below_p)
-  thus "compact (e\<cdot>x)" by (rule compactI)
+  from assms have "adm (\<lambda>y. x \<notsqsubseteq> y)" by (rule compactD)
+  then have "adm (\<lambda>y. x \<notsqsubseteq> p\<cdot>y)" by (rule adm_subst [OF cont_Rep_cfun2])
+  then have "adm (\<lambda>y. e\<cdot>x \<notsqsubseteq> y)" by (simp add: e_below_iff_below_p)
+  then show "compact (e\<cdot>x)" by (rule compactI)
 qed
 
 lemma compact_e_iff: "compact (e\<cdot>x) \<longleftrightarrow> compact x"
-by (rule iffI [OF compact_e_rev compact_e])
+  by (rule iffI [OF compact_e_rev compact_e])
 
 text \<open>Deflations from ep-pairs\<close>
 
 lemma deflation_e_p: "deflation (e oo p)"
-by (simp add: deflation.intro e_p_below)
+  by (simp add: deflation.intro e_p_below)
 
 lemma deflation_e_d_p:
   assumes "deflation d"
@@ -253,9 +250,9 @@
     by (simp add: e_below_iff_below_p below)
   have "finite ((\<lambda>x. e\<cdot>x) ` (\<lambda>x. d\<cdot>x) ` range (\<lambda>x. p\<cdot>x))"
     by (simp add: finite_image)
-  hence "finite (range (\<lambda>x. (e oo d oo p)\<cdot>x))"
+  then have "finite (range (\<lambda>x. (e oo d oo p)\<cdot>x))"
     by (simp add: image_image)
-  thus "finite {x. (e oo d oo p)\<cdot>x = x}"
+  then show "finite {x. (e oo d oo p)\<cdot>x = x}"
     by (rule finite_range_imp_finite_fixes)
 qed
 
@@ -265,32 +262,27 @@
   shows "deflation (p oo d oo e)"
 proof -
   interpret d: deflation d by fact
-  {
-    fix x
+  have p_d_e_below: "(p oo d oo e)\<cdot>x \<sqsubseteq> x" for x
+  proof -
     have "d\<cdot>(e\<cdot>x) \<sqsubseteq> e\<cdot>x"
       by (rule d.below)
-    hence "p\<cdot>(d\<cdot>(e\<cdot>x)) \<sqsubseteq> p\<cdot>(e\<cdot>x)"
+    then have "p\<cdot>(d\<cdot>(e\<cdot>x)) \<sqsubseteq> p\<cdot>(e\<cdot>x)"
       by (rule monofun_cfun_arg)
-    hence "(p oo d oo e)\<cdot>x \<sqsubseteq> x"
-      by simp
-  }
-  note p_d_e_below = this
+    then show ?thesis by simp
+  qed
   show ?thesis
   proof
-    fix x
-    show "(p oo d oo e)\<cdot>x \<sqsubseteq> x"
+    show "(p oo d oo e)\<cdot>x \<sqsubseteq> x" for x
       by (rule p_d_e_below)
-  next
-    fix x
-    show "(p oo d oo e)\<cdot>((p oo d oo e)\<cdot>x) = (p oo d oo e)\<cdot>x"
+    show "(p oo d oo e)\<cdot>((p oo d oo e)\<cdot>x) = (p oo d oo e)\<cdot>x" for x
     proof (rule below_antisym)
       show "(p oo d oo e)\<cdot>((p oo d oo e)\<cdot>x) \<sqsubseteq> (p oo d oo e)\<cdot>x"
         by (rule p_d_e_below)
       have "p\<cdot>(d\<cdot>(d\<cdot>(d\<cdot>(e\<cdot>x)))) \<sqsubseteq> p\<cdot>(d\<cdot>(e\<cdot>(p\<cdot>(d\<cdot>(e\<cdot>x)))))"
         by (intro monofun_cfun_arg d)
-      hence "p\<cdot>(d\<cdot>(e\<cdot>x)) \<sqsubseteq> p\<cdot>(d\<cdot>(e\<cdot>(p\<cdot>(d\<cdot>(e\<cdot>x)))))"
+      then have "p\<cdot>(d\<cdot>(e\<cdot>x)) \<sqsubseteq> p\<cdot>(d\<cdot>(e\<cdot>(p\<cdot>(d\<cdot>(e\<cdot>x)))))"
         by (simp only: d.idem)
-      thus "(p oo d oo e)\<cdot>x \<sqsubseteq> (p oo d oo e)\<cdot>((p oo d oo e)\<cdot>x)"
+      then show "(p oo d oo e)\<cdot>x \<sqsubseteq> (p oo d oo e)\<cdot>((p oo d oo e)\<cdot>x)"
         by simp
     qed
   qed
@@ -305,16 +297,16 @@
   show ?thesis
   proof (rule finite_deflation_intro)
     have "deflation d" ..
-    thus "deflation (p oo d oo e)"
+    then show "deflation (p oo d oo e)"
       using d by (rule deflation_p_d_e)
   next
     have "finite ((\<lambda>x. d\<cdot>x) ` range (\<lambda>x. e\<cdot>x))"
       by (rule d.finite_image)
-    hence "finite ((\<lambda>x. p\<cdot>x) ` (\<lambda>x. d\<cdot>x) ` range (\<lambda>x. e\<cdot>x))"
+    then have "finite ((\<lambda>x. p\<cdot>x) ` (\<lambda>x. d\<cdot>x) ` range (\<lambda>x. e\<cdot>x))"
       by (rule finite_imageI)
-    hence "finite (range (\<lambda>x. (p oo d oo e)\<cdot>x))"
+    then have "finite (range (\<lambda>x. (p oo d oo e)\<cdot>x))"
       by (simp add: image_image)
-    thus "finite {x. (p oo d oo e)\<cdot>x = x}"
+    then show "finite {x. (p oo d oo e)\<cdot>x = x}"
       by (rule finite_range_imp_finite_fixes)
   qed
 qed
@@ -324,41 +316,42 @@
 subsection \<open>Uniqueness of ep-pairs\<close>
 
 lemma ep_pair_unique_e_lemma:
-  assumes 1: "ep_pair e1 p" and 2: "ep_pair e2 p"
+  assumes 1: "ep_pair e1 p"
+    and 2: "ep_pair e2 p"
   shows "e1 \<sqsubseteq> e2"
 proof (rule cfun_belowI)
   fix x
   have "e1\<cdot>(p\<cdot>(e2\<cdot>x)) \<sqsubseteq> e2\<cdot>x"
     by (rule ep_pair.e_p_below [OF 1])
-  thus "e1\<cdot>x \<sqsubseteq> e2\<cdot>x"
+  then show "e1\<cdot>x \<sqsubseteq> e2\<cdot>x"
     by (simp only: ep_pair.e_inverse [OF 2])
 qed
 
-lemma ep_pair_unique_e:
-  "\<lbrakk>ep_pair e1 p; ep_pair e2 p\<rbrakk> \<Longrightarrow> e1 = e2"
-by (fast intro: below_antisym elim: ep_pair_unique_e_lemma)
+lemma ep_pair_unique_e: "ep_pair e1 p \<Longrightarrow> ep_pair e2 p \<Longrightarrow> e1 = e2"
+  by (fast intro: below_antisym elim: ep_pair_unique_e_lemma)
 
 lemma ep_pair_unique_p_lemma:
-  assumes 1: "ep_pair e p1" and 2: "ep_pair e p2"
+  assumes 1: "ep_pair e p1"
+    and 2: "ep_pair e p2"
   shows "p1 \<sqsubseteq> p2"
 proof (rule cfun_belowI)
   fix x
   have "e\<cdot>(p1\<cdot>x) \<sqsubseteq> x"
     by (rule ep_pair.e_p_below [OF 1])
-  hence "p2\<cdot>(e\<cdot>(p1\<cdot>x)) \<sqsubseteq> p2\<cdot>x"
+  then have "p2\<cdot>(e\<cdot>(p1\<cdot>x)) \<sqsubseteq> p2\<cdot>x"
     by (rule monofun_cfun_arg)
-  thus "p1\<cdot>x \<sqsubseteq> p2\<cdot>x"
+  then show "p1\<cdot>x \<sqsubseteq> p2\<cdot>x"
     by (simp only: ep_pair.e_inverse [OF 2])
 qed
 
-lemma ep_pair_unique_p:
-  "\<lbrakk>ep_pair e p1; ep_pair e p2\<rbrakk> \<Longrightarrow> p1 = p2"
-by (fast intro: below_antisym elim: ep_pair_unique_p_lemma)
+lemma ep_pair_unique_p: "ep_pair e p1 \<Longrightarrow> ep_pair e p2 \<Longrightarrow> p1 = p2"
+  by (fast intro: below_antisym elim: ep_pair_unique_p_lemma)
+
 
 subsection \<open>Composing ep-pairs\<close>
 
 lemma ep_pair_ID_ID: "ep_pair ID ID"
-by standard simp_all
+  by standard simp_all
 
 lemma ep_pair_comp:
   assumes "ep_pair e1 p1" and "ep_pair e2 p2"
@@ -371,7 +364,7 @@
     by simp
   have "e1\<cdot>(p1\<cdot>(p2\<cdot>y)) \<sqsubseteq> p2\<cdot>y"
     by (rule ep1.e_p_below)
-  hence "e2\<cdot>(e1\<cdot>(p1\<cdot>(p2\<cdot>y))) \<sqsubseteq> e2\<cdot>(p2\<cdot>y)"
+  then have "e2\<cdot>(e1\<cdot>(p1\<cdot>(p2\<cdot>y))) \<sqsubseteq> e2\<cdot>(p2\<cdot>y)"
     by (rule monofun_cfun_arg)
   also have "e2\<cdot>(p2\<cdot>y) \<sqsubseteq> y"
     by (rule ep2.e_p_below)
@@ -387,19 +380,19 @@
 lemma e_strict [simp]: "e\<cdot>\<bottom> = \<bottom>"
 proof -
   have "\<bottom> \<sqsubseteq> p\<cdot>\<bottom>" by (rule minimal)
-  hence "e\<cdot>\<bottom> \<sqsubseteq> e\<cdot>(p\<cdot>\<bottom>)" by (rule monofun_cfun_arg)
+  then have "e\<cdot>\<bottom> \<sqsubseteq> e\<cdot>(p\<cdot>\<bottom>)" by (rule monofun_cfun_arg)
   also have "e\<cdot>(p\<cdot>\<bottom>) \<sqsubseteq> \<bottom>" by (rule e_p_below)
   finally show "e\<cdot>\<bottom> = \<bottom>" by simp
 qed
 
 lemma e_bottom_iff [simp]: "e\<cdot>x = \<bottom> \<longleftrightarrow> x = \<bottom>"
-by (rule e_eq_iff [where y="\<bottom>", unfolded e_strict])
+  by (rule e_eq_iff [where y="\<bottom>", unfolded e_strict])
 
 lemma e_defined: "x \<noteq> \<bottom> \<Longrightarrow> e\<cdot>x \<noteq> \<bottom>"
-by simp
+  by simp
 
 lemma p_strict [simp]: "p\<cdot>\<bottom> = \<bottom>"
-by (rule e_inverse [where x="\<bottom>", unfolded e_strict])
+  by (rule e_inverse [where x="\<bottom>", unfolded e_strict])
 
 lemmas stricts = e_strict p_strict