Closures.thy
changeset 191 f6a603be52d6
parent 190 b73478aaf33e
child 193 2a5ac68db24b
equal deleted inserted replaced
190:b73478aaf33e 191:f6a603be52d6
   151 proof -
   151 proof -
   152   from assms obtain r::"'a rexp" where eq: "lang r = A" by auto
   152   from assms obtain r::"'a rexp" where eq: "lang r = A" by auto
   153   have fin: "finite (pders_lang B r)" by (rule finite_pders_lang)
   153   have fin: "finite (pders_lang B r)" by (rule finite_pders_lang)
   154   
   154   
   155   have "Ders_lang B (lang r) = (\<Union> lang ` (pders_lang B r))"
   155   have "Ders_lang B (lang r) = (\<Union> lang ` (pders_lang B r))"
   156     by (simp add: Ders_pders)
   156     by (simp add: Ders_pders pders_lang_def)
   157   also have "\<dots> = lang (\<Uplus>(pders_lang B r))" using fin by simp
   157   also have "\<dots> = lang (\<Uplus>(pders_lang B r))" using fin by simp
   158   finally have "Ders_lang B A = lang (\<Uplus>(pders_lang B r))" using eq
   158   finally have "Ders_lang B A = lang (\<Uplus>(pders_lang B r))" using eq
   159     by simp
   159     by simp
   160   then show "regular (Ders_lang B A)" by auto
   160   then show "regular (Ders_lang B A)" by auto
   161 qed
   161 qed