overview
play

Overview overview7.4 Introduction Modelling parallel systems - PowerPoint PPT Presentation

Overview overview7.4 Introduction Modelling parallel systems Linear Time Properties Regular Properties Linear Temporal Logic (LTL) Computation-Tree Logic Equivalences and Abstraction bisimulation CTL, CTL*-equivalence computing the


  1. Analysis by abstraction from stutter steps stutter5.4-4 simplified TS ℓ 1 x =2 y =4 ℓ 1 x =2 y =4 ℓ 1 x =2 y =4 z =3 z =3 z =3 representation ℓ 2 x =1 y =4 z =3 ℓ 2 x =1 y =4 ℓ 2 x =1 y =4 z =3 z =3 z =3 z =3 z =3 ℓ 3 x =1 y =2 ℓ 3 x =1 y =2 ℓ 3 x =1 y =2 z =3 z =3 z =3 ℓ 1 x =1 y =2 ℓ 1 x =1 y =2 ℓ 1 x =1 y =2 z =1 z =1 z =1 z =1 z =1 z =1 ℓ 2 x =2 y =2 z =1 ℓ 2 x =2 y =2 ℓ 2 x =2 y =2 z =1 z =1 z =0 z =0 z =0 ℓ 3 x =2 y =1 z =1 ℓ 3 x =2 y =1 ℓ 3 x =2 y =1 z =1 z =1 . . . . . . . . . ℓ 1 x =2 y =1 z =0 ℓ 1 x =2 y =1 z =0 ℓ 1 x =2 y =1 z =0 . . . . . . . . . 21 / 444

  2. Overview overview7.4-stutter-trace Introduction Modelling parallel systems Linear Time Properties Regular Properties Linear Temporal Logic (LTL) Computation-Tree Logic (CTL) Equivalences and Abstraction bisimulation, CTL/CTL*-equivalence computing the bisimulation quotient abstraction stutter steps stutter LT relations ← ← ← − − − stutter bisimulation simulation relations 22 / 444

  3. Remind: trace relations stutter5.4-5-remind 23 / 444

  4. Remind: trace relations stutter5.4-5-remind trace equivalence for paths π 1 π 1 π 1 , π 2 π 2 π 2 are trace equivalent iff trace ( π 1 ) = trace ( π 2 ) trace ( π 1 ) = trace ( π 2 ) trace ( π 1 ) = trace ( π 2 ) 24 / 444

  5. Remind: trace relations stutter5.4-5-remind trace equivalence for paths π 1 π 1 π 1 , π 2 π 2 π 2 are trace equivalent iff trace ( π 1 ) = trace ( π 2 ) trace ( π 1 ) = trace ( π 2 ) trace ( π 1 ) = trace ( π 2 ) trace inclusion for TS: Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) ∀ π 1 ∈ Traces ( T 1 ) ∀ π 1 ∈ Traces ( T 1 ) ∀ π 1 ∈ Traces ( T 1 ) ∃ π 2 ∈ Traces ( T 2 ) ∃ π 2 ∈ Traces ( T 2 ) ∃ π 2 ∈ Traces ( T 2 ) s.t. π 1 π 1 π 1 , π 2 π 2 π 2 are trace equivalent 25 / 444

  6. Remind: trace relations stutter5.4-5-remind trace equivalence for paths π 1 π 1 π 1 , π 2 π 2 π 2 are trace equivalent iff trace ( π 1 ) = trace ( π 2 ) trace ( π 1 ) = trace ( π 2 ) trace ( π 1 ) = trace ( π 2 ) trace inclusion for TS: Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) ∀ π 1 ∈ Traces ( T 1 ) ∀ π 1 ∈ Traces ( T 1 ) ∀ π 1 ∈ Traces ( T 1 ) ∃ π 2 ∈ Traces ( T 2 ) ∃ π 2 ∈ Traces ( T 2 ) ∃ π 2 ∈ Traces ( T 2 ) s.t. π 1 π 1 π 1 , π 2 π 2 π 2 are trace equivalent trace equivalence for TS: Traces ( T 1 ) ⊆ Traces ( T 2 ) ∧ Traces ( T 2 ) ⊆ Traces ( T 1 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) ∧ ∧ Traces ( T 2 ) ⊆ Traces ( T 1 ) Traces ( T 2 ) ⊆ Traces ( T 1 ) 26 / 444

  7. Remind: trace relations stutter5.4-5-remind trace equivalence for paths π 1 π 1 π 1 , π 2 π 2 π 2 are trace equivalent iff trace ( π 1 ) = trace ( π 2 ) trace ( π 1 ) = trace ( π 2 ) trace ( π 1 ) = trace ( π 2 ) trace inclusion for TS: Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) ∀ π 1 ∈ Traces ( T 1 ) ∀ π 1 ∈ Traces ( T 1 ) ∀ π 1 ∈ Traces ( T 1 ) ∃ π 2 ∈ Traces ( T 2 ) ∃ π 2 ∈ Traces ( T 2 ) ∃ π 2 ∈ Traces ( T 2 ) s.t. π 1 π 1 π 1 , π 2 π 2 π 2 are trace equivalent trace equivalence for TS: Traces ( T 1 ) ⊆ Traces ( T 2 ) ∧ Traces ( T 2 ) ⊆ Traces ( T 1 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) ∧ ∧ Traces ( T 2 ) ⊆ Traces ( T 1 ) Traces ( T 2 ) ⊆ Traces ( T 1 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) iff for each LT property E E E : T 2 | T 2 | T 2 | = E = E = E implies T 1 | T 1 | T 1 | = E = E = E 27 / 444

  8. Remind: trace relations stutter5.4-5-remind trace equivalence for paths π 1 π 1 π 1 , π 2 π 2 π 2 are trace equivalent iff trace ( π 1 ) = trace ( π 2 ) trace ( π 1 ) = trace ( π 2 ) trace ( π 1 ) = trace ( π 2 ) trace inclusion for TS: Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) ∀ π 1 ∈ Traces ( T 1 ) ∀ π 1 ∈ Traces ( T 1 ) ∀ π 1 ∈ Traces ( T 1 ) ∃ π 2 ∈ Traces ( T 2 ) ∃ π 2 ∈ Traces ( T 2 ) ∃ π 2 ∈ Traces ( T 2 ) s.t. π 1 π 1 π 1 , π 2 π 2 π 2 are trace equivalent trace equivalence for TS: Traces ( T 1 ) ⊆ Traces ( T 2 ) ∧ Traces ( T 2 ) ⊆ Traces ( T 1 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) ∧ ∧ Traces ( T 2 ) ⊆ Traces ( T 1 ) Traces ( T 2 ) ⊆ Traces ( T 1 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) iff for each LT property E E E : T 2 | T 2 | T 2 | = E = E implies T 1 | = E T 1 | T 1 | = E = E = E � � �    trace equivalent TS satisfy the same LTL formulas 28 / 444

  9. Stutter equivalence for paths stutter5.4-stutter-equiv-paths 29 / 444

  10. Stutter equivalence for paths stutter5.4-stutter-equiv-paths stutter equivalence for infinite path fragments: 30 / 444

  11. Stutter equivalence for paths stutter5.4-stutter-equiv-paths stutter equivalence for infinite path fragments: ∆ ∆ ∆ π 1 = π 2 π 1 π 1 = π 2 = π 2 iff there exists an infinite word 2 AP � ω s.t. the 2 AP � ω 2 AP � ω � � � A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ traces of π 1 π 1 π 1 and π 2 π 2 π 2 are of the form A 0 . . . A 0 A 1 . . . A 1 A 2 . . . A 2 . . . A 0 . . . A 0 A 1 . . . A 1 A 2 . . . A 2 . . . A 0 . . . A 0 A 1 . . . A 1 A 2 . . . A 2 . . . 31 / 444

  12. Stutter equivalence for paths stutter5.4-stutter-equiv-paths stutter equivalence for infinite path fragments: ∆ ∆ ∆ π 1 = π 2 π 1 π 1 = π 2 = π 2 iff there exists an infinite word 2 AP � ω s.t. the 2 AP � ω 2 AP � ω � � � A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ traces of π 1 π 1 π 1 and π 2 π 2 π 2 are of the form A n 0 A n 0 A n 0 0 A n 1 0 A n 1 0 A n 1 1 A n 2 1 A n 2 1 A n 2 2 . . . 2 . . . 2 . . . n 0 , n 1 , n 2 , . . . ≥ 1 where n 0 , n 1 , n 2 , . . . n 0 , n 1 , n 2 , . . . are natural numbers ≥ 1 ≥ 1 32 / 444

  13. Stutter equivalence for paths stutter5.4-stutter-equiv-paths stutter equivalence for infinite path fragments: ∆ ∆ ∆ π 1 = π 2 π 1 π 1 = π 2 = π 2 iff there exists an infinite word 2 AP � ω s.t. the 2 AP � ω 2 AP � ω � � � A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ traces of π 1 π 1 π 1 and π 2 π 2 π 2 are of the form A 0+ A 1+ A 2+ . . . A 0+ A 1+ A 2+ . . . A 0+ A 1+ A 2+ . . . 33 / 444

  14. Stutter equivalence for paths stutter5.4-stutter-equiv-paths stutter equivalence for infinite path fragments: ∆ ∆ ∆ π 1 = π 2 π 1 π 1 = π 2 = π 2 iff there exists an infinite word 2 AP � ω s.t. the 2 AP � ω 2 AP � ω � � � A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ traces of π 1 π 1 π 1 and π 2 π 2 π 2 are of the form A 0+ A 1+ A 2+ . . . A 0+ A 1+ A 2+ . . . A 0+ A 1+ A 2+ . . . stutter equivalence for finite path fragments: ∆ ∆ ∆ π 1 ˆ π 1 π 1 ˆ ˆ = ˆ = ˆ = ˆ π 2 π 2 π 2 iff there exists a finite word 2 AP � + s.t. 2 AP � + 2 AP � + � � � A 0 A 1 A 2 . . . A n ∈ A 0 A 1 A 2 . . . A n ∈ A 0 A 1 A 2 . . . A n ∈ the traces of ˆ π 1 π 1 ˆ ˆ π 1 and ˆ π 2 π 2 ˆ ˆ π 2 are in A 0+ A 1+ A 2+ . . . A n + A 0+ A 1+ A 2+ . . . A n + A 0+ A 1+ A 2+ . . . A n + 34 / 444

  15. Stutter trace relations for TS stutter5.4-5 stutter equivalence for infinite path fragments: ∆ ∆ ∆ π 1 = π 2 π 1 π 1 = π 2 = π 2 iff there exists an infinite word 2 AP � ω s.t. the 2 AP � ω 2 AP � ω � � � A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ traces of π 1 π 1 π 1 and π 2 π 2 π 2 are of the form A 0+ A 1+ A 2+ . . . A 0+ A 1+ A 2+ . . . A 0+ A 1+ A 2+ . . . 35 / 444

  16. Stutter trace relations for TS stutter5.4-5 stutter equivalence for infinite path fragments: ∆ ∆ ∆ π 1 = π 2 π 1 π 1 = π 2 = π 2 iff there exists an infinite word 2 AP � ω s.t. the 2 AP � ω 2 AP � ω � � � A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ traces of π 1 π 1 π 1 and π 2 π 2 π 2 are of the form A 0+ A 1+ A 2+ . . . A 0+ A 1+ A 2+ . . . A 0+ A 1+ A 2+ . . . stutter trace inclusion for transition systems: T 1 � T 2 T 1 � T 2 T 1 � T 2 iff for all paths π 1 π 1 π 1 of T 1 T 1 T 1 there exists a path π 2 π 2 of T 2 π 2 T 2 T 2 ∆ ∆ ∆ s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 36 / 444

  17. Example: stutter trace inclusion � � � stutter5.4-5-ex T 1 � T 2 T 1 � T 2 T 1 � T 2 iff ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∆ ∆ ∆ s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 = ∅ = ∅ = ∅ = { a } = { a } = { a } = { b } = { b } = { b } 37 / 444

  18. Example: stutter trace inclusion � � � stutter5.4-5-ex T 1 � T 2 T 1 � T 2 T 1 � T 2 iff ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∆ ∆ ∆ s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 = ∅ = ∅ = ∅ � � � = { a } = { a } = { a } = { b } = { b } = { b } 38 / 444

  19. Example: stutter trace inclusion � � � stutter5.4-5-ex T 1 � T 2 T 1 � T 2 T 1 � T 2 iff ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∆ ∆ ∆ s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 = ∅ = ∅ = ∅ � � � = { a } = { a } = { a } = { b } = { b } = { b } ( ∅ + { b } + { a } + ) ω all traces have the form ( ∅ + { b } + { a } + ) ω ( ∅ + { b } + { a } + ) ω or ( ∅ + { b } + { a } + ) ∗ ∅ ω ( ∅ + { b } + { a } + ) ∗ ∅ ω ( ∅ + { b } + { a } + ) ∗ ∅ ω 39 / 444

  20. Stutter trace inclusion and LTL stutter5.4-5-LTL T 1 � T 2 T 1 � T 2 T 1 � T 2 iff ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∆ ∆ ∆ s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 Does stutter trace inclusion preserve LTL properties? 40 / 444

  21. Stutter trace inclusion and LTL stutter5.4-5-LTL T 1 � T 2 T 1 � T 2 T 1 � T 2 iff ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∆ ∆ ∆ s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 Does stutter trace inclusion preserve LTL properties? � � �       ϕ i.e., for all LTL formulas ϕ ϕ : T 1 � T 2 T 1 � T 2 T 1 � T 2 ∧ ∧ ∧ T 2 | T 2 | T 2 | = ϕ = ϕ = ϕ implies T 1 | T 1 | T 1 | = ϕ = ϕ = ϕ 41 / 444

  22. Stutter trace inclusion and LTL stutter5.4-5-LTL T 1 � T 2 T 1 � T 2 T 1 � T 2 iff ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∆ ∆ ∆ s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 Does stutter trace inclusion preserve LTL properties? � � �       ϕ i.e., for all LTL formulas ϕ ϕ : T 1 � T 2 T 1 � T 2 T 1 � T 2 ∧ ∧ ∧ T 2 | T 2 | T 2 | = ϕ = ϕ = ϕ implies T 1 | T 1 | T 1 | = ϕ = ϕ = ϕ answer: no 42 / 444

  23. Stutter trace inclusion and LTL stutter5.4-5-LTL T 1 � T 2 T 1 � T 2 T 1 � T 2 iff ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∆ ∆ ∆ s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 Does stutter trace inclusion preserve LTL properties? � � �       ϕ i.e., for all LTL formulas ϕ ϕ : T 1 � T 2 T 1 � T 2 T 1 � T 2 ∧ ∧ ∧ T 2 | T 2 | T 2 | = ϕ = ϕ = ϕ implies T 1 | T 1 | T 1 | = ϕ = ϕ = ϕ answer: no Example: LTL formulas of the form � a � a � a 43 / 444

  24. Stutter trace inclusion and LTL \� \� \� stutter5.4-5-thm T 1 � T 2 T 1 � T 2 T 1 � T 2 iff ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∆ ∆ ∆ s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 Let T 1 T 1 T 1 and T 2 T 2 T 2 are TS without terminal states and ϕ ϕ ϕ an LTL \� \� formula. Then: \� T 1 � T 2 T 1 � T 2 T 1 � T 2 ∧ ∧ ∧ T 2 | T 2 | T 2 | = ϕ = ϕ = ϕ implies T 1 | T 1 | T 1 | = ϕ = ϕ = ϕ 44 / 444

  25. Stutter trace inclusion and LTL \� \� \� stutter5.4-5-thm T 1 � T 2 T 1 � T 2 T 1 � T 2 iff ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∆ ∆ ∆ s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 Let T 1 T 1 T 1 and T 2 T 2 T 2 are TS without terminal states and ϕ ϕ ϕ an LTL \� \� formula. Then: \� T 1 � T 2 T 1 � T 2 T 1 � T 2 ∧ ∧ ∧ T 2 | T 2 | T 2 | = ϕ = ϕ = ϕ implies T 1 | T 1 | T 1 | = ϕ = ϕ = ϕ where LTL \� \� = = = LTL without the next operator � � � \� 45 / 444

  26. ∆ ∆ ∆ = Stutter trace equivalence = = for TS stutter5.4-5a 46 / 444

  27. ∆ ∆ ∆ = Stutter trace equivalence = = for TS stutter5.4-5a stutter trace inclusion T 1 � T 2 T 1 � T 2 T 1 � T 2 ∆ ∆ ∆ ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 47 / 444

  28. ∆ ∆ ∆ = Stutter trace equivalence = = for TS stutter5.4-5a stutter trace inclusion T 1 � T 2 T 1 � T 2 T 1 � T 2 ∆ ∆ ∆ ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 stutter trace equivalence ∆ ∆ ∆ T 1 T 1 T 1 = T 2 = T 2 = T 2 iff T 1 � T 2 T 1 � T 2 T 1 � T 2 and T 2 � T 1 T 2 � T 1 T 2 � T 1 48 / 444

  29. ∆ ∆ ∆ = Stutter trace equivalence = = for TS stutter5.4-5a stutter trace inclusion T 1 � T 2 T 1 � T 2 T 1 � T 2 ∆ ∆ ∆ ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 stutter trace equivalence ∆ ∆ ∆ T 1 T 1 T 1 = T 2 = T 2 = T 2 iff T 1 � T 2 T 1 � T 2 T 1 � T 2 and T 2 � T 1 T 2 � T 1 T 2 � T 1 � � �    kernel of � � � , i.e., coarsest equivalence that refines � � � 49 / 444

  30. ∆ ∆ ∆ = Stutter trace equivalence = = for TS stutter5.4-5a stutter trace inclusion T 1 � T 2 T 1 � T 2 T 1 � T 2 ∆ ∆ ∆ ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 For all LTL \� \� formulas ϕ ϕ ϕ : \� T 1 � T 2 T 1 � T 2 T 1 � T 2 ∧ ∧ ∧ T 2 | T 2 | T 2 | = ϕ = ϕ = ϕ implies T 1 | T 1 | T 1 | = ϕ = ϕ = ϕ stutter trace equivalence ∆ ∆ ∆ T 1 T 1 T 1 = T 2 = T 2 = T 2 iff T 1 � T 2 T 1 � T 2 T 1 � T 2 and T 2 � T 1 T 2 � T 1 T 2 � T 1 � � �    kernel of � � � , i.e., coarsest equivalence that refines � � � 50 / 444

  31. ∆ ∆ ∆ = Stutter trace equivalence = = for TS stutter5.4-5a stutter trace inclusion T 1 � T 2 T 1 � T 2 T 1 � T 2 ∆ ∆ ∆ ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∀ π 1 ∈ Paths ( T 1 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) ∃ π 2 ∈ Paths ( T 2 ) s.t. π 1 π 1 π 1 = π 2 = π 2 = π 2 For all LTL \� \� formulas ϕ ϕ ϕ : \� T 1 � T 2 T 1 � T 2 T 1 � T 2 ∧ ∧ ∧ T 2 | T 2 | T 2 | = ϕ = ϕ = ϕ implies T 1 | T 1 | T 1 | = ϕ = ϕ = ϕ stutter trace equivalence ∆ ∆ ∆ T 1 T 1 T 1 = T 2 = T 2 = T 2 iff T 1 � T 2 T 1 � T 2 T 1 � T 2 and T 2 � T 1 T 2 � T 1 T 2 � T 1 ∆ ∆ ∆ If T 1 T 1 T 1 = T 2 = T 2 = T 2 then T 1 T 1 T 1 and T 2 T 2 T 2 are LTL \� \� equivalent. \� 51 / 444

  32. Correct or wrong? stutter5.4-13a ∆ ∆ ∆ = = = 52 / 444

  33. Correct or wrong? stutter5.4-13a ∆ ∆ ∆ = = = correct 53 / 444

  34. Correct or wrong? stutter5.4-13a ∆ ∆ ∆ = = = correct T 2 have the form • + + • + + or • ω ω ω + + The traces of T 1 T 1 T 1 and T 2 T 2 54 / 444

  35. Correct or wrong? stutter5.4-13a ∆ ∆ ∆ = = = correct T 2 have the form • + + • + + or • ω ω ω + + The traces of T 1 T 1 T 1 and T 2 T 2 ∆ ∆ ∆ = = = 55 / 444

  36. Correct or wrong? stutter5.4-13a ∆ ∆ ∆ = = = correct T 2 have the form • + + • + + or • ω ω ω + + The traces of T 1 T 1 T 1 and T 2 T 2 wrong ∆ ∆ ∆ = = = 56 / 444

  37. Correct or wrong? stutter5.4-13a ∆ ∆ ∆ = = = correct T 2 have the form • + + • + + or • ω ω ω + + The traces of T 1 T 1 T 1 and T 2 T 2 wrong ∆ ∆ ∆ = = = T 1 has a finite trace • + + • , while T 2 + T 1 T 2 T 1 T 2 has not 57 / 444

  38. Correct or wrong? stutter5.4-13b If T 1 T 1 T 1 and T 2 T 2 T 2 are TS over AP AP AP then: ∆ ∆ ∆ T 1 ∼ T 2 T 1 = T 2 T 1 ∼ T 2 T 1 ∼ T 2 implies T 1 T 1 = T 2 = T 2 58 / 444

  39. Correct or wrong? stutter5.4-13b If T 1 T 1 T 1 and T 2 T 2 T 2 are TS over AP AP AP then: ∆ ∆ ∆ T 1 ∼ T 2 T 1 = T 2 T 1 ∼ T 2 T 1 ∼ T 2 implies T 1 T 1 = T 2 = T 2 ր տ ր ր տ տ bisimulation stutter trace equivalence equivalence 59 / 444

  40. Correct or wrong? stutter5.4-13b If T 1 T 1 T 1 and T 2 T 2 T 2 are TS over AP AP AP then: ∆ ∆ ∆ T 1 ∼ T 2 T 1 = T 2 T 1 ∼ T 2 T 1 ∼ T 2 implies T 1 T 1 = T 2 = T 2 ր տ ր ր տ տ bisimulation stutter trace equivalence equivalence correct 60 / 444

  41. Correct or wrong? stutter5.4-13b If T 1 T 1 T 1 and T 2 T 2 T 2 are TS over AP AP AP then: ∆ ∆ ∆ T 1 ∼ T 2 T 1 = T 2 T 1 ∼ T 2 T 1 ∼ T 2 implies T 1 T 1 = T 2 = T 2 ր տ ր ր տ տ bisimulation stutter trace equivalence equivalence correct , as • T 1 ∼ T 2 T 1 ∼ T 2 T 1 ∼ T 2 implies Traces ( T 1 ) = Traces ( T 2 ) Traces ( T 1 ) = Traces ( T 2 ) Traces ( T 1 ) = Traces ( T 2 ) • trace equivalent paths are stutter trace equivalent 61 / 444

  42. Correct or wrong? stutter5.4-13b If T 1 T 1 T 1 and T 2 T 2 T 2 are TS over AP AP AP then: ∆ ∆ ∆ T 1 ∼ T 2 T 1 = T 2 T 1 ∼ T 2 T 1 ∼ T 2 implies T 1 T 1 = T 2 = T 2 ր տ ր ր տ տ bisimulation stutter trace equivalence equivalence correct , as • T 1 ∼ T 2 T 1 ∼ T 2 T 1 ∼ T 2 implies Traces ( T 1 ) = Traces ( T 2 ) Traces ( T 1 ) = Traces ( T 2 ) Traces ( T 1 ) = Traces ( T 2 ) • trace equivalent paths are stutter trace equivalent obviously: Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) Traces ( T 1 ) ⊆ Traces ( T 2 ) implies T 1 � T 2 T 1 � T 2 T 1 � T 2 62 / 444

  43. Stutter-insensitive LT properties stutter5.4-st-ins-prop 63 / 444

  44. Stutter-insensitive LT properties stutter5.4-st-ins-prop stutter equivalence for infinite words 64 / 444

  45. Stutter-insensitive LT properties stutter5.4-st-ins-prop 2 AP � ω 2 AP � ω 2 AP � ω : � � � stutter equivalence for infinite words σ 1 σ 1 σ 1 , σ 2 ∈ σ 2 ∈ σ 2 ∈ 65 / 444

  46. Stutter-insensitive LT properties stutter5.4-st-ins-prop 2 AP � ω 2 AP � ω 2 AP � ω : � � � stutter equivalence for infinite words σ 1 σ 1 σ 1 , σ 2 ∈ σ 2 ∈ σ 2 ∈ ∆ ∆ ∆ σ 1 = σ 2 σ 1 σ 1 = σ 2 = σ 2 iff there exists an infinite word 2 AP � ω s.t. σ 1 2 AP � ω 2 AP � ω � � � A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ σ 1 σ 1 and σ 2 σ 2 σ 2 A 0+ A 1+ A 2+ . . . are in A 0+ A 1+ A 2+ . . . A 0+ A 1+ A 2+ . . . 66 / 444

  47. Stutter-insensitive LT properties stutter5.4-st-ins-prop 2 AP � ω 2 AP � ω : 2 AP � ω � � � stutter equivalence for infinite words σ 1 σ 1 , σ 2 ∈ σ 1 σ 2 ∈ σ 2 ∈ ∆ ∆ ∆ σ 1 = σ 2 σ 1 σ 1 = σ 2 = σ 2 iff there exists an infinite word 2 AP � ω s.t. σ 1 2 AP � ω 2 AP � ω � � � A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ σ 1 σ 1 and σ 2 σ 2 σ 2 A 0+ A 1+ A 2+ . . . are in A 0+ A 1+ A 2+ . . . A 0+ A 1+ A 2+ . . . 2 AP � ω be an LT property. E 2 AP � ω 2 AP � ω � � � Let E ⊆ E ⊆ E ⊆ E E is called 2 AP � ω 2 AP � ω 2 AP � ω : � � � stutter-insensitive iff for all σ 1 σ 1 , σ 2 ∈ σ 1 σ 2 ∈ σ 2 ∈ ∆ ∆ ∆ if σ 1 ∈ E σ 1 ∈ E σ 1 ∈ E and σ 1 σ 1 σ 1 = σ 2 = σ 2 = σ 2 then σ 2 ∈ E σ 2 ∈ E σ 2 ∈ E 67 / 444

  48. Stutter-insensitive LT properties stutter5.4-st-ins-prop 2 AP � ω 2 AP � ω 2 AP � ω : � � � stutter equivalence for infinite words σ 1 σ 1 σ 1 , σ 2 ∈ σ 2 ∈ σ 2 ∈ ∆ ∆ ∆ σ 1 = σ 2 σ 1 σ 1 = σ 2 = σ 2 iff there exists an infinite word 2 AP � ω s.t. σ 1 2 AP � ω 2 AP � ω � � � A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ A 0 A 1 A 2 . . . ∈ σ 1 σ 1 and σ 2 σ 2 σ 2 A 0+ A 1+ A 2+ . . . are in A 0+ A 1+ A 2+ . . . A 0+ A 1+ A 2+ . . . 2 AP � ω be an LT property. E 2 AP � ω 2 AP � ω � � � Let E ⊆ E ⊆ E ⊆ E E is called 2 AP � ω 2 AP � ω 2 AP � ω : � � � stutter-insensitive iff for all σ 1 σ 1 , σ 2 ∈ σ 1 σ 2 ∈ σ 2 ∈ ∆ ∆ ∆ if σ 1 ∈ E σ 1 ∈ E σ 1 ∈ E and σ 1 σ 1 σ 1 = σ 2 = σ 2 = σ 2 then σ 2 ∈ E σ 2 ∈ E σ 2 ∈ E Example: if ϕ ϕ ϕ is an LTL \� \� formula then \� E = Words ( ϕ ) E = Words ( ϕ ) E = Words ( ϕ ) is stutter-insensitive 68 / 444

  49. Stutter-insensitive LT properties stutter5.4-st-ins-prop Let T 1 T 1 T 1 , T 2 T 2 T 2 be two TS and E E E a stutter-insensitive LT-property. Then: T 1 � T 2 T 1 � T 2 T 1 � T 2 and T 2 | T 2 | T 2 | = E = E = E implies T 1 | T 1 | T 1 | = E = E = E 69 / 444

  50. Stutter-insensitive LT properties stutter5.4-st-ins-prop Let T 1 T 1 T 1 , T 2 T 2 T 2 be two TS and E E E a stutter-insensitive LT-property. Then: T 1 � T 2 T 1 � T 2 T 1 � T 2 and T 2 | T 2 | T 2 | = E = E = E implies T 1 | T 1 | T 1 | = E = E = E Let T 1 T 1 T 1 , T 2 T 2 T 2 be two TS and ϕ ϕ ϕ an LTL \� \� formula. \� T 1 � T 2 T 2 | = ϕ T 1 | = ϕ T 1 � T 2 T 1 � T 2 and T 2 | T 2 | = ϕ = ϕ implies T 1 | T 1 | = ϕ = ϕ 70 / 444

  51. Stutter-insensitive LT properties stutter5.4-st-ins-prop Let T 1 T 1 T 1 , T 2 T 2 T 2 be two TS and E E E a stutter-insensitive LT-property. Then: T 1 � T 2 T 1 � T 2 T 1 � T 2 and T 2 | T 2 | T 2 | = E = E = E implies T 1 | T 1 | T 1 | = E = E = E Let T 1 T 1 T 1 , T 2 T 2 be two TS and ϕ T 2 ϕ an LTL \� ϕ \� formula. \� T 1 � T 2 T 2 | = ϕ T 1 | = ϕ T 1 � T 2 T 1 � T 2 and T 2 | T 2 | = ϕ = ϕ implies T 1 | T 1 | = ϕ = ϕ remind: if ϕ ϕ ϕ is an LTL \� \� formula then \� E = Words ( ϕ ) E = Words ( ϕ ) E = Words ( ϕ ) is stutter-insensitive 71 / 444

  52. Overview overview7.4a Introduction Modelling parallel systems Linear Time Properties Regular Properties Linear Temporal Logic (LTL) Computation-Tree Logic (CTL) Equivalences and Abstraction bisimulation, CTL/CTL*-equivalence computing the bisimulation quotient abstraction stutter steps stutter LT relations stutter bisimulation ← ← ← − − − simulation relations 72 / 444

  53. Stutter bisimulation stutter5.4-def-stutter-bis 73 / 444

  54. Stutter bisimulation stutter5.4-def-stutter-bis Let T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) be a TS, possibly with terminal states. 74 / 444

  55. Stutter bisimulation stutter5.4-def-stutter-bis Let T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) be a TS, possibly with terminal states. T A stutter bisimulation for T T is .... 75 / 444

  56. Stutter bisimulation stutter5.4-def-stutter-bis Let T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) be a TS, possibly with terminal states. T R A stutter bisimulation for T T is a binary relation R R on S S S s.t. 76 / 444

  57. Stutter bisimulation stutter5.4-def-stutter-bis Let T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) be a TS, possibly with terminal states. T R A stutter bisimulation for T T is a binary relation R R ( s 1 , s 2 ) ∈ R on S S S s.t. for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : (1) labeling condition (2) simulation condition up to stuttering “ s 2 s 2 s 2 can mimick all transitions of of s 1 s 1 s 1 ” (3) simulation condition up to stuttering “ s 1 s 1 s 1 can mimick all transitions of of s 2 s 2 s 2 ” 77 / 444

  58. Stutter bisimulation stutter5.4-def-stutter-bis Let T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) be a TS, possibly with terminal states. T R A stutter bisimulation for T T is a binary relation R R ( s 1 , s 2 ) ∈ R on S S S s.t. for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : L ( s 1 ) = L ( s 2 ) (1) labeling condition: L ( s 1 ) = L ( s 2 ) L ( s 1 ) = L ( s 2 ) (2) simulation condition up to stuttering “ s 2 s 2 s 2 can mimick all transitions of of s 1 s 1 s 1 ” (3) simulation condition up to stuttering “ s 1 s 1 s 1 can mimick all transitions of of s 2 s 2 s 2 ” 78 / 444

  59. Stutter bisimulation stutter5.4-def-stutter-bis Let T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) T = ( S , Act , → , S 0 , AP , L ) be a TS, possibly with terminal states. T R A stutter bisimulation for T T is a binary relation R R ( s 1 , s 2 ) ∈ R on S S S s.t. for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : L ( s 1 ) = L ( s 2 ) (1) labeling condition: L ( s 1 ) = L ( s 2 ) L ( s 1 ) = L ( s 2 ) (2) simulation condition up to stuttering “ s 2 s 2 s 2 can mimick all transitions of of s 1 s 1 s 1 ” (3) simulation condition up to stuttering “ s 1 s 1 s 1 can mimick all transitions of of s 2 s 2 s 2 ” 79 / 444

  60. Simulation condition stutter5.4-def-stutter-bis A stutter bisimulation for T T T is a binary relation R R R on S S s.t. for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : ( s 1 , s 2 ) ∈ R S . . . . . . . . . . . . . . . . . . (2) simulation condition up to stuttering s 1 - R R - s 2 R s 1 s 2 s 1 s 2 s ′ s ′ s ′ 1 1 1 80 / 444

  61. Simulation condition stutter5.4-def-stutter-bis A stutter bisimulation for T T T is a binary relation R R R on S S s.t. for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : ( s 1 , s 2 ) ∈ R S . . . . . . . . . . . . . . . . . . (2) simulation condition up to stuttering s 1 - R R R - s 2 s 1 s 2 s 1 s 2 s ′ s ′ s ′ 1 1 1 with ( s ′ ( s ′ ( s ′ 1 , s 2 ) / 1 , s 2 ) / 1 , s 2 ) / ∈ R ∈ R ∈ R 81 / 444

  62. Simulation condition stutter5.4-def-stutter-bis A stutter bisimulation for T T T is a binary relation R R R on S S s.t. for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : S . . . . . . . . . . . . . . . . . . (2) simulation condition up to stuttering s 1 - R R R - s 2 s 1 - R R - s 2 R s 1 s 2 s 1 s 2 s 1 s 2 s 1 s 2 can be u 1 u 1 u 1 completed to s ′ s ′ s ′ . . . 1 1 1 . . . . . . u n u n u n with ( s ′ ( s ′ ( s ′ 1 , s 2 ) / 1 , s 2 ) / 1 , s 2 ) / ∈ R ∈ R ∈ R s ′ s ′ s ′ s ′ s ′ s ′ - R R R - 1 2 1 1 2 2 82 / 444

  63. Simulation condition stutter5.4-def-stutter-bis A stutter bisimulation for T T T is a binary relation R R R on S S s.t. for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : S . . . . . . . . . . . . . . . . . . (2) simulation condition up to stuttering s 1 - R R R - s 2 s 1 - R R - s 2 R s 1 s 2 s 1 s 2 s 1 s 2 s 1 s 2 can be u 1 u 1 u 1 completed to s ′ s ′ s ′ . . . 1 1 1 . . . s 1 - R - u i s 1 - R - u i s 1 - R - u i . . . u n u n u n with ( s ′ ( s ′ ( s ′ 1 , s 2 ) / 1 , s 2 ) / 1 , s 2 ) / ∈ R ∈ R ∈ R s ′ s ′ s ′ s ′ s ′ s ′ - R R R - 1 2 1 1 2 2 83 / 444

  64. Stutter bisimulation for a TS stutter5.4-stbis Let T T T be a transition system wih state space S S S . A stutter bisimulation for T T T is a binary relation R R R on S S S such that for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : (1) L ( s 1 ) = L ( s 2 ) L ( s 1 ) = L ( s 2 ) L ( s 1 ) = L ( s 2 ) s 1 → s ′ ( s ′ for each transition s 1 → s ′ s 1 → s ′ 1 with ( s ′ ( s ′ 1 , s 2 ) / ∈ R (2) 1 , s 2 ) / 1 , s 2 ) / ∈ R ∈ R 1 1 s 2 u 1 u 2 . . . u n s ′ there exists a path fragment s 2 u 1 u 2 . . . u n s ′ s 2 u 1 u 2 . . . u n s ′ 2 2 2 . . . s.t. . . . . . . (3) . . . . . . . . . 84 / 444

  65. Stutter bisimulation for a TS stutter5.4-stbis Let T T T be a transition system wih state space S S S . A stutter bisimulation for T T T is a binary relation R R R on S S S such that for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : (1) L ( s 1 ) = L ( s 2 ) L ( s 1 ) = L ( s 2 ) L ( s 1 ) = L ( s 2 ) s 1 → s ′ ( s ′ for each transition s 1 → s ′ s 1 → s ′ 1 with ( s ′ ( s ′ 1 , s 2 ) / ∈ R (2) 1 , s 2 ) / 1 , s 2 ) / ∈ R ∈ R 1 1 s 2 u 1 u 2 . . . u n s ′ there exists a path fragment s 2 u 1 u 2 . . . u n s ′ s 2 u 1 u 2 . . . u n s ′ 2 2 2 n ≥ 0 ( s 1 , u i ) ∈ R 1 ≤ i ≤ n s.t. n ≥ 0 n ≥ 0 and ( s 1 , u i ) ∈ R ( s 1 , u i ) ∈ R for 1 ≤ i ≤ n 1 ≤ i ≤ n (3) . . . . . . . . . 85 / 444

  66. Stutter bisimulation for a TS stutter5.4-stbis Let T T T be a transition system wih state space S S S . A stutter bisimulation for T T T is a binary relation R R R on S S S such that for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : (1) L ( s 1 ) = L ( s 2 ) L ( s 1 ) = L ( s 2 ) L ( s 1 ) = L ( s 2 ) s 1 → s ′ ( s ′ for each transition s 1 → s ′ s 1 → s ′ 1 with ( s ′ ( s ′ 1 , s 2 ) / ∈ R (2) 1 , s 2 ) / 1 , s 2 ) / ∈ R ∈ R 1 1 s 2 u 1 u 2 . . . u n s ′ there exists a path fragment s 2 u 1 u 2 . . . u n s ′ s 2 u 1 u 2 . . . u n s ′ 2 2 2 n ≥ 0 ( s 1 , u i ) ∈ R 1 ≤ i ≤ n s.t. n ≥ 0 n ≥ 0 and ( s 1 , u i ) ∈ R ( s 1 , u i ) ∈ R for 1 ≤ i ≤ n 1 ≤ i ≤ n (3) symmetric condition 86 / 444

  67. Stutter bisimulation for a TS stutter5.4-stbis Let T T T be a transition system wih state space S S S . A stutter bisimulation for T T T is a binary relation R R R on S S S such that for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : (1) L ( s 1 ) = L ( s 2 ) L ( s 1 ) = L ( s 2 ) L ( s 1 ) = L ( s 2 ) s 1 → s ′ ( s ′ for each transition s 1 → s ′ s 1 → s ′ 1 with ( s ′ ( s ′ 1 , s 2 ) / ∈ R (2) 1 , s 2 ) / 1 , s 2 ) / ∈ R ∈ R 1 1 s 2 u 1 u 2 . . . u n s ′ there exists a path fragment s 2 u 1 u 2 . . . u n s ′ s 2 u 1 u 2 . . . u n s ′ 2 2 2 n ≥ 0 ( s 1 , u i ) ∈ R 1 ≤ i ≤ n s.t. n ≥ 0 n ≥ 0 and ( s 1 , u i ) ∈ R ( s 1 , u i ) ∈ R for 1 ≤ i ≤ n 1 ≤ i ≤ n for each transition s 2 → s ′ s 2 → s ′ s 2 → s ′ 2 with ( s 1 , s ′ ( s 1 , s ′ ( s 1 , s ′ (3) 2 ) / 2 ) / 2 ) / ∈ R ∈ R ∈ R 2 2 there exists a path fragment s 1 v 1 v 2 . . . v n s ′ s 1 v 1 v 2 . . . v n s ′ s 1 v 1 v 2 . . . v n s ′ 1 1 1 n ≥ 0 ( v i , s 2 ) ∈ R 1 ≤ i ≤ n s.t. n ≥ 0 n ≥ 0 and ( v i , s 2 ) ∈ R ( v i , s 2 ) ∈ R for 1 ≤ i ≤ n 1 ≤ i ≤ n 87 / 444

  68. ≈ T Stutter bisimulation equivalence ≈ T ≈ T stutter5.4-def-approx 88 / 444

  69. ≈ T Stutter bisimulation equivalence ≈ T ≈ T stutter5.4-def-approx Let T T T be a transition system wih state space S S S . A stutter bisimulation for T T is a binary relation R T R R on S S S such that for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : (1) labeling condition (2) and (3) mutual simulation condition 89 / 444

  70. ≈ T Stutter bisimulation equivalence ≈ T ≈ T stutter5.4-def-approx Let T T T be a transition system wih state space S S S . A stutter bisimulation for T T T is a binary relation R R R on S S S such that for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : (1) labeling condition (2) and (3) mutual simulation condition stutter bisimulation equivalence ≈ T ≈ T ≈ T : 90 / 444

  71. ≈ T Stutter bisimulation equivalence ≈ T ≈ T stutter5.4-def-approx Let T T T be a transition system wih state space S S S . A stutter bisimulation for T T T is a binary relation R R R on S S S such that for all ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R : ( s 1 , s 2 ) ∈ R (1) labeling condition (2) and (3) mutual simulation condition stutter bisimulation equivalence ≈ T ≈ T ≈ T : s 1 ≈ T s 2 s 1 ≈ T s 2 s 1 ≈ T s 2 iff there exists a stutter bisimulation R R R for T T T s.t. ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R 91 / 444

  72. ≈ T ≈ T ≈ T is an equivalence stutter5.4-10 92 / 444

  73. ≈ T ≈ T ≈ T is an equivalence stutter5.4-10 symmetry: if s 1 ≈ T s 2 s 1 ≈ T s 2 s 1 ≈ T s 2 then s 2 ≈ T s 1 s 2 ≈ T s 1 s 2 ≈ T s 1 93 / 444

  74. ≈ T ≈ T ≈ T is an equivalence stutter5.4-10 s 1 ≈ T s 2 s 2 ≈ T s 1 symmetry: if s 1 ≈ T s 2 s 1 ≈ T s 2 then s 2 ≈ T s 1 s 2 ≈ T s 1 proof: R ( s 1 , s 2 ) ∈ R if R R is a stutter bisimulation with ( s 1 , s 2 ) ∈ R ( s 1 , s 2 ) ∈ R then R − 1 = R − 1 = R − 1 = � � � � � � ( t 2 , t 1 ) : ( t 1 , t 2 ) ∈ R ( t 2 , t 1 ) : ( t 1 , t 2 ) ∈ R ( t 2 , t 1 ) : ( t 1 , t 2 ) ∈ R is a stutter bisimulation that contains ( s 2 , s 1 ) ( s 2 , s 1 ) ( s 2 , s 1 ). 94 / 444

  75. ≈ T ≈ T ≈ T is an equivalence stutter5.4-10 symmetry: if s 1 ≈ T s 2 s 1 ≈ T s 2 s 1 ≈ T s 2 then s 2 ≈ T s 1 s 2 ≈ T s 1 s 2 ≈ T s 1 s ≈ T s reflexivity: s ≈ T s s ≈ T s for all states s s s 95 / 444

  76. ≈ T ≈ T ≈ T is an equivalence stutter5.4-10 symmetry: if s 1 ≈ T s 2 s 1 ≈ T s 2 s 1 ≈ T s 2 then s 2 ≈ T s 1 s 2 ≈ T s 1 s 2 ≈ T s 1 s ≈ T s reflexivity: s ≈ T s s ≈ T s for all states s s s proof: � � � � � � R = ( s , s ) : s ∈ S R = R = ( s , s ) : s ∈ S ( s , s ) : s ∈ S is a stutter bisimulation 96 / 444

  77. ≈ T ≈ T ≈ T is an equivalence stutter5.4-10 symmetry: if s 1 ≈ T s 2 s 1 ≈ T s 2 s 1 ≈ T s 2 then s 2 ≈ T s 1 s 2 ≈ T s 1 s 2 ≈ T s 1 s ≈ T s reflexivity: s ≈ T s s ≈ T s for all states s s s s 1 ≈ T s 2 s 2 ≈ T s 3 s 1 ≈ T s 3 transitivity: s 1 ≈ T s 2 s 1 ≈ T s 2 and s 2 ≈ T s 3 s 2 ≈ T s 3 implies s 1 ≈ T s 3 s 1 ≈ T s 3 97 / 444

  78. ≈ T ≈ T ≈ T is an equivalence stutter5.4-10 symmetry: if s 1 ≈ T s 2 s 1 ≈ T s 2 s 1 ≈ T s 2 then s 2 ≈ T s 1 s 2 ≈ T s 1 s 2 ≈ T s 1 s ≈ T s reflexivity: s ≈ T s s ≈ T s for all states s s s s 1 ≈ T s 2 s 2 ≈ T s 3 s 1 ≈ T s 3 transitivity: s 1 ≈ T s 2 s 1 ≈ T s 2 and s 2 ≈ T s 3 s 2 ≈ T s 3 implies s 1 ≈ T s 3 s 1 ≈ T s 3 Proof: Let R 1 , 2 R 1 , 2 R 1 , 2 and R 2 , 3 R 2 , 3 R 2 , 3 be stutter bisimulations s.t. ( s 1 , s 2 ) ∈ R 1 , 2 , ( s 2 , s 3 ) ∈ R 2 , 3 ( s 1 , s 2 ) ∈ R 1 , 2 , ( s 2 , s 3 ) ∈ R 2 , 3 ( s 1 , s 2 ) ∈ R 1 , 2 , ( s 2 , s 3 ) ∈ R 2 , 3 R = R 1 , 2 ◦ R 2 , 3 Show that R = R 1 , 2 ◦ R 2 , 3 R = R 1 , 2 ◦ R 2 , 3 is a stutter bisimulation. 98 / 444

  79. s 1 s 1 s 1 R 1 , 2 s 2 s 2 s 2 R 2 , 3 s 3 s 3 s 3 R 1 , 2 R 1 , 2 R 2 , 3 R 2 , 3 s ′ s ′ s ′ 1 1 1 99 / 444

  80. s 1 s 1 s 1 R 1 , 2 s 2 s 2 s 2 R 2 , 3 s 3 s 3 s 3 R 1 , 2 R 1 , 2 R 2 , 3 R 2 , 3 u 1 u 1 u 1 . . . . . . . . . u j − 1 u j − 1 u j − 1 u j u j u j . . . . . . . . . u k − 1 u k − 1 u k − 1 u k u k u k . . . . . . . . . u m u m u m s ′ s ′ s ′ s ′ s ′ s ′ R 1 , 2 R 1 , 2 R 1 , 2 1 2 1 1 2 2 100 / 444

Download Presentation
Download Policy: The content available on the website is offered to you 'AS IS' for your personal information and use only. It cannot be commercialized, licensed, or distributed on other websites without prior consent from the author. To download a presentation, simply click this link. If you encounter any difficulties during the download process, it's possible that the publisher has removed the file from their server.

Recommend


More recommend