Nominal-General/Nominal2_Base.thy
changeset 2013 3078fab2d7a6
parent 2003 b53e98bfb298
child 2310 dd3b9c046c7d
equal deleted inserted replaced
2012:a48a6f88f76e 2013:3078fab2d7a6
  1197 
  1197 
  1198 lemma supp_finite_set_at_base:
  1198 lemma supp_finite_set_at_base:
  1199   assumes a: "finite S"
  1199   assumes a: "finite S"
  1200   shows "supp S = atom ` S"
  1200   shows "supp S = atom ` S"
  1201 proof -
  1201 proof -
  1202   have fin: "finite (atom ` S)" 
  1202   have fin: "finite (atom ` S)" using a by simp
  1203     using a by (simp add: finite_imageI) 
       
  1204   have "supp S = supp (atom ` S)" by (rule atom_image_supp)
  1203   have "supp S = supp (atom ` S)" by (rule atom_image_supp)
  1205   also have "\<dots> = atom ` S" using fin by (simp add: supp_finite_atom_set)
  1204   also have "\<dots> = atom ` S" using fin by (simp add: supp_finite_atom_set)
  1206   finally show "supp S = atom ` S" by simp
  1205   finally show "supp S = atom ` S" by simp
  1207 qed
  1206 qed
  1208 
  1207