tuned proofs -- avoid z3, which is unavailable on arm64-linux;

--- a/src/HOL/Analysis/Infinite_Sum.thy	Sat Oct 30 13:26:33 2021 +0200
+++ b/src/HOL/Analysis/Infinite_Sum.thy	Sat Oct 30 17:10:10 2021 +0200
@@ -320,7 +320,7 @@
   fixes f :: "'a \<Rightarrow> 'b::{topological_ab_group_add,t2_space}"
   assumes "f summable_on B" and "f summable_on A" and AB: "A \<subseteq> B"
   shows infsum_Diff: "infsum f (B - A) = infsum f B - infsum f A"
-  by (smt (z3) AB assms(1) assms(2) finite_subsets_at_top_neq_bot infsum_def summable_on_def has_sum_Diff has_sum_def tendsto_Lim)
+  by (metis AB assms has_sum_Diff infsumI summable_on_def)
 
 lemma has_sum_mono_neutral:
   fixes f :: "'a\<Rightarrow>'b::{ordered_comm_monoid_add,linorder_topology}"
@@ -440,7 +440,7 @@
     proof -
       from ev_P
       obtain F' where \<open>finite F'\<close> and \<open>F' \<subseteq> A\<close> and P_sup_F': \<open>finite F \<and> F \<supseteq> F' \<and> F \<subseteq> A \<Longrightarrow> P F\<close> for F
-        apply atomize_elim by (simp add: eventually_finite_subsets_at_top)
+        by atomize_elim (simp add: eventually_finite_subsets_at_top)
       define F where \<open>F = F' \<union> F1 \<union> F2\<close>
       have \<open>finite F\<close> and \<open>F \<subseteq> A\<close>
         using F_def P_def[abs_def] that \<open>finite F'\<close> \<open>F' \<subseteq> A\<close> by auto
@@ -448,7 +448,7 @@
         by (metis F_def \<open>F \<subseteq> A\<close> P_def P_sup_F' \<open>finite F\<close> le_supE order_refl)
 
       from dist_F have \<open>dist (sum (\<lambda>x. norm (f x)) F) (sum (\<lambda>x. norm (f x)) F2) < 2*d\<close>
-        by (smt (z3) P_def dist_norm real_norm_def that(2))
+        by (smt (verit, ccfv_threshold) P_def dist_norm real_norm_def that(2))
       then have \<open>norm (sum (\<lambda>x. norm (f x)) (F-F2)) < 2*d\<close>
         unfolding dist_norm
         by (metis F_def \<open>finite F\<close> sum_diff sup_commute sup_ge1)
@@ -458,7 +458,7 @@
         by (metis F_def \<open>finite F\<close> dist_norm sum_diff sup_commute sup_ge1)
 
       from dist_F have \<open>dist (sum (\<lambda>x. norm (f x)) F) (sum (\<lambda>x. norm (f x)) F1) < 2*d\<close>
-        by (smt (z3) P_def dist_norm real_norm_def that(1))
+        by (smt (verit, best) P_def dist_norm real_norm_def that(1))
       then have \<open>norm (sum (\<lambda>x. norm (f x)) (F-F1)) < 2*d\<close>
         unfolding dist_norm
         by (metis F_def \<open>finite F\<close> inf_sup_ord(3) order_trans sum_diff sup_ge2)
@@ -652,7 +652,7 @@
   have \<open>has_sum (\<lambda>x. f x + g x) A (infsum f A + infsum g A)\<close>
     by (simp add: assms(1) assms(2) has_sum_add)
   then show ?thesis
-    by (smt (z3) finite_subsets_at_top_neq_bot infsum_def summable_on_def has_sum_def tendsto_Lim)
+    using infsumI by blast
 qed
 
 
@@ -1187,7 +1187,7 @@
         unfolding FMB_def eventually_finite_subsets_at_top
         apply (rule exI[of _ G])
         using \<open>G \<subseteq> Sigma A B\<close> \<open>finite G\<close> that G_sum apply auto
-        by (smt (z3) Sigma_Un_distrib1 dual_order.trans subset_Un_eq)
+        by (meson Sigma_mono dual_order.refl order_trans)
       ultimately have \<open>\<forall>\<^sub>F x in FMB. E (sum b M, a)\<close>
         by (smt (verit, best) DDE' eventually_elim2)
       then show \<open>E (sum b M, a)\<close>

--- a/src/HOL/Library/Extended_Nonnegative_Real.thy	Sat Oct 30 13:26:33 2021 +0200
+++ b/src/HOL/Library/Extended_Nonnegative_Real.thy	Sat Oct 30 17:10:10 2021 +0200
@@ -1175,14 +1175,15 @@
 
 (* Contributed by Dominique Unruh *)
 lemma ennreal_of_enat_plus[simp]: \<open>ennreal_of_enat (a+b) = ennreal_of_enat a + ennreal_of_enat b\<close>
-  apply (induction a)
-  apply auto
-  by (smt (z3) add.commute add.right_neutral enat.exhaust enat.simps(4) enat.simps(5) ennreal_add_left_cancel ennreal_of_enat_def infinity_ennreal_def of_nat_add of_nat_eq_enat plus_enat_simps(2))
+  apply (induct a)
+   apply (metis enat.exhaust ennreal_add_eq_top ennreal_of_enat_enat ennreal_of_enat_infty infinity_ennreal_def of_nat_add plus_enat_simps(1) plus_eq_infty_iff_enat)
+  apply simp
+  done
 
 (* Contributed by Dominique Unruh *)
 lemma sum_ennreal_of_enat[simp]: "(\<Sum>i\<in>I. ennreal_of_enat (f i)) = ennreal_of_enat (sum f I)"
-  apply (induction I rule: infinite_finite_induct) 
-  by (auto simp: sum_nonneg)
+  by (induct I rule: infinite_finite_induct) (auto simp: sum_nonneg)
+
 
 subsection \<open>Topology on \<^typ>\<open>ennreal\<close>\<close>