Cookies disclaimer

I agree Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our website without changing the browser settings you grant us permission to store that information on your device.

Homework 05.1

This is the task corresponding to the first part of homework 5.

Resources

Download Files

Definitions File

theory Defs
  imports "HOL-IMP.Small_Step" "HOL-IMP.BExp" "HOL-IMP.Star"
begin



end

Template File

theory Submission
  imports Defs
begin

fun small :: "com * state ⇒ (com * state) option" where
  "small _ = undefined"

theorem small_small_step_equiv: "(c,s) → (c',s') ⟷ small (c,s) = Some (c',s')"
  sorry

fun smalls :: "nat ⇒ com * state ⇒ (com * state) option" where
  "smalls _ _ = undefined"

theorem smalls_small_steps_equiv:
  "(∃s'. (c,s) →* (c',s')) ⟷ (
    if c' = SKIP then
      (∃n. smalls n (c, s) = None)
    else
      (∃n s'. smalls n (c, s) = Some (c', s'))
   )"
  sorry

end

Check File

theory Check
  imports Submission
begin

theorem small_small_step_equiv: "(c,s) → (c',s') ⟷ small (c,s) = Some (c',s')"
  by (rule Submission.small_small_step_equiv)

theorem smalls_small_steps_equiv:
  "(∃s'. (c,s) →* (c',s')) ⟷ (
    if c' = SKIP then
      (∃n. smalls n (c, s) = None)
    else
      (∃n s'. smalls n (c, s) = Some (c', s'))
   )"
  by (rule Submission.smalls_small_steps_equiv)

end

Terms and Conditions