src/HOL/Multivariate_Analysis/Brouwer_Fixpoint.thy
changeset 44821 a92f65e174cf
parent 44457 d366fa5551ef
child 44890 22f665a2e91c
equal deleted inserted replaced
44797:e0da66339e47 44821:a92f65e174cf
    91     int (card {s \<in> simplices. \<not> compo s \<and> card {f \<in> faces. face f s \<and> compo' f} = 2} * 2)"
    91     int (card {s \<in> simplices. \<not> compo s \<and> card {f \<in> faces. face f s \<and> compo' f} = 2} * 2)"
    92     using lem1[unfolded lem3 lem2 lem5] by auto
    92     using lem1[unfolded lem3 lem2 lem5] by auto
    93   have even_minus_odd:"\<And>x y. even x \<Longrightarrow> odd (y::int) \<Longrightarrow> odd (x - y)" using assms by auto
    93   have even_minus_odd:"\<And>x y. even x \<Longrightarrow> odd (y::int) \<Longrightarrow> odd (x - y)" using assms by auto
    94   have odd_minus_even:"\<And>x y. odd x \<Longrightarrow> even (y::int) \<Longrightarrow> odd (x - y)" using assms by auto
    94   have odd_minus_even:"\<And>x y. odd x \<Longrightarrow> even (y::int) \<Longrightarrow> odd (x - y)" using assms by auto
    95   show ?thesis unfolding even_nat_def unfolding card_eq_setsum and lem4[THEN sym] and *[unfolded card_eq_setsum]
    95   show ?thesis unfolding even_nat_def unfolding card_eq_setsum and lem4[THEN sym] and *[unfolded card_eq_setsum]
    96     unfolding card_eq_setsum[THEN sym] apply (rule odd_minus_even) unfolding zadd_int[THEN sym] apply(rule odd_plus_even)
    96     unfolding card_eq_setsum[THEN sym] apply (rule odd_minus_even) unfolding of_nat_add apply(rule odd_plus_even)
    97     apply(rule assms(7)[unfolded even_nat_def]) unfolding int_mult by auto qed
    97     apply(rule assms(7)[unfolded even_nat_def]) unfolding int_mult by auto qed
    98 
    98 
    99 subsection {* The odd/even result for faces of complete vertices, generalized. *}
    99 subsection {* The odd/even result for faces of complete vertices, generalized. *}
   100 
   100 
   101 lemma card_1_exists: "card s = 1 \<longleftrightarrow> (\<exists>!x. x \<in> s)" unfolding One_nat_def
   101 lemma card_1_exists: "card s = 1 \<longleftrightarrow> (\<exists>!x. x \<in> s)" unfolding One_nat_def