--- a/src/HOL/IMP/Abs_Int1.thy Tue Jan 16 09:12:16 2018 +0100
+++ b/src/HOL/IMP/Abs_Int1.thy Tue Jan 16 09:30:00 2018 +0100
@@ -59,7 +59,7 @@
proof(simp add: CS_def AI_def)
assume 1: "pfp (step' \<top>) (bot c) = Some C"
have pfp': "step' \<top> C \<le> C" by(rule pfp_pfp[OF 1])
- have 2: "step (\<gamma>\<^sub>o \<top>) (\<gamma>\<^sub>c C) \<le> \<gamma>\<^sub>c C" \<comment>"transfer the pfp'"
+ have 2: "step (\<gamma>\<^sub>o \<top>) (\<gamma>\<^sub>c C) \<le> \<gamma>\<^sub>c C" \<comment> \<open>transfer the pfp'\<close>
proof(rule order_trans)
show "step (\<gamma>\<^sub>o \<top>) (\<gamma>\<^sub>c C) \<le> \<gamma>\<^sub>c (step' \<top> C)" by(rule step_step')
show "... \<le> \<gamma>\<^sub>c C" by (metis mono_gamma_c[OF pfp'])