# HG changeset patch # User hoelzl # Date 1454997860 -3600 # Node ID 4a35e3945cab1008f435e92e945bba51790fca0d # Parent acfc4ad7b76a87c510e1d68729cdc746f5f5fb46 add transfer rule for countable diff -r acfc4ad7b76a -r 4a35e3945cab src/HOL/Library/Countable_Set.thy --- a/src/HOL/Library/Countable_Set.thy Tue Feb 09 06:39:31 2016 +0100 +++ b/src/HOL/Library/Countable_Set.thy Tue Feb 09 07:04:20 2016 +0100 @@ -312,6 +312,11 @@ qed qed +lemma transfer_countable[transfer_rule]: + "bi_unique R \ rel_fun (rel_set R) op = countable countable" + by (rule rel_funI, erule (1) bi_unique_rel_set_lemma) + (auto dest: countable_image_inj_on) + subsection \Uncountable\ abbreviation uncountable where @@ -323,10 +328,10 @@ lemma uncountable_bij_betw: "bij_betw f A B \ uncountable B \ uncountable A" unfolding bij_betw_def by (metis countable_image) - + lemma uncountable_infinite: "uncountable A \ infinite A" by (metis countable_finite) - + lemma uncountable_minus_countable: "uncountable A \ countable B \ uncountable (A - B)" using countable_Un[of B "A - B"] assms by auto