src/HOL/Algebra/Group.thy
changeset 68551 b680e74eb6f2
parent 68517 6b5f15387353
child 68555 22d51874f37d
equal deleted inserted replaced
68550:516e81f75957 68551:b680e74eb6f2
  1436 lemma (in monoid) units_of_inv: 
  1436 lemma (in monoid) units_of_inv: 
  1437   assumes "x \<in> Units G"
  1437   assumes "x \<in> Units G"
  1438   shows "m_inv (units_of G) x = m_inv G x"
  1438   shows "m_inv (units_of G) x = m_inv G x"
  1439   by (simp add: assms group.inv_equality units_group units_of_carrier units_of_mult units_of_one)
  1439   by (simp add: assms group.inv_equality units_group units_of_carrier units_of_mult units_of_one)
  1440 
  1440 
       
  1441 lemma units_of_units [simp] : "Units (units_of G) = Units G"
       
  1442   unfolding units_of_def Units_def by force
       
  1443 
  1441 lemma (in group) surj_const_mult: "a \<in> carrier G \<Longrightarrow> (\<lambda>x. a \<otimes> x) ` carrier G = carrier G"
  1444 lemma (in group) surj_const_mult: "a \<in> carrier G \<Longrightarrow> (\<lambda>x. a \<otimes> x) ` carrier G = carrier G"
  1442   apply (auto simp add: image_def)
  1445   apply (auto simp add: image_def)
  1443   by (metis inv_closed inv_solve_left m_closed)
  1446   by (metis inv_closed inv_solve_left m_closed)
  1444 
  1447 
  1445 lemma (in group) l_cancel_one [simp]: "x \<in> carrier G \<Longrightarrow> a \<in> carrier G \<Longrightarrow> x \<otimes> a = x \<longleftrightarrow> a = one G"
  1448 lemma (in group) l_cancel_one [simp]: "x \<in> carrier G \<Longrightarrow> a \<in> carrier G \<Longrightarrow> x \<otimes> a = x \<longleftrightarrow> a = one G"