(* Title: HOL/SPARK/Manual/Simple_Greatest_Common_Divisor.thy
Author: Stefan Berghofer
Copyright: secunet Security Networks AG
*)
theory Simple_Greatest_Common_Divisor
imports "HOL-SPARK.SPARK"
begin
spark_proof_functions
gcd = "gcd :: int \<Rightarrow> int \<Rightarrow> int"
spark_open "simple_greatest_common_divisor/g_c_d"
spark_vc procedure_g_c_d_4
using \<open>0 < d\<close> \<open>gcd c d = gcd m n\<close>
by (simp add: gcd_non_0_int)
spark_vc procedure_g_c_d_9
using \<open>0 \<le> c\<close> \<open>gcd c 0 = gcd m n\<close>
by simp
spark_end
end