src/HOL/ex/Transfer_Ex.thy

clarified XML signature (again) -- coincide with basic Markup without explicit dependency;

header {* Various examples for transfer procedure *}

theory Transfer_Ex
imports Main
begin

lemma ex1: "(x::nat) + y = y + x"
  by auto

lemma "0 \<le> (y\<Colon>int) \<Longrightarrow> 0 \<le> (x\<Colon>int) \<Longrightarrow> x + y = y + x"
  by (fact ex1 [transferred])

lemma ex2: "(a::nat) div b * b + a mod b = a"
  by (rule mod_div_equality)

lemma "0 \<le> (b\<Colon>int) \<Longrightarrow> 0 \<le> (a\<Colon>int) \<Longrightarrow> a div b * b + a mod b = a"
  by (fact ex2 [transferred])

lemma ex3: "ALL (x::nat). ALL y. EX z. z >= x + y"
  by auto

lemma "\<forall>x\<ge>0\<Colon>int. \<forall>y\<ge>0. \<exists>z\<ge>0. x + y \<le> z"
  by (fact ex3 [transferred nat_int])

lemma ex4: "(x::nat) >= y \<Longrightarrow> (x - y) + y = x"
  by auto

lemma "0 \<le> (x\<Colon>int) \<Longrightarrow> 0 \<le> (y\<Colon>int) \<Longrightarrow> y \<le> x \<Longrightarrow> tsub x y + y = x"
  by (fact ex4 [transferred])

lemma ex5: "(2::nat) * \<Sum>{..n} = n * (n + 1)"
  by (induct n rule: nat_induct, auto)

lemma "0 \<le> (n\<Colon>int) \<Longrightarrow> 2 * \<Sum>{0..n} = n * (n + 1)"
  by (fact ex5 [transferred])

lemma "0 \<le> (n\<Colon>nat) \<Longrightarrow> 2 * \<Sum>{0..n} = n * (n + 1)"
  by (fact ex5 [transferred, transferred])

end