--- a/src/HOL/Library/Equipollence.thy Fri Sep 20 19:07:10 2024 +0200
+++ b/src/HOL/Library/Equipollence.thy Fri Sep 20 19:51:08 2024 +0200
@@ -6,10 +6,10 @@
subsection\<open>Eqpoll\<close>
-definition eqpoll :: "'a set \<Rightarrow> 'b set \<Rightarrow> bool" (infixl "\<approx>" 50)
+definition eqpoll :: "'a set \<Rightarrow> 'b set \<Rightarrow> bool" (infixl \<open>\<approx>\<close> 50)
where "eqpoll A B \<equiv> \<exists>f. bij_betw f A B"
-definition lepoll :: "'a set \<Rightarrow> 'b set \<Rightarrow> bool" (infixl "\<lesssim>" 50)
+definition lepoll :: "'a set \<Rightarrow> 'b set \<Rightarrow> bool" (infixl \<open>\<lesssim>\<close> 50)
where "lepoll A B \<equiv> \<exists>f. inj_on f A \<and> f ` A \<subseteq> B"
definition lesspoll :: "'a set \<Rightarrow> 'b set \<Rightarrow> bool" (infixl \<open>\<prec>\<close> 50)