quantified differential invariants
play

Quantified Differential Invariants Andr e Platzer Carnegie Mellon - PowerPoint PPT Presentation

Quantified Differential Invariants Andr e Platzer Carnegie Mellon University, Pittsburgh, PA 0.5 0.4 0.3 0.2 1.0 0.1 0.8 0.6 0.4 0.2 Andr e Platzer (CMU) Quantified Differential Invariants HSCC 1 / 21 Outline Motivation 1


  1. Model for Distributed Hybrid Systems Q: How to model distributed hybrid systems Model (Distributed Hybrid Systems) Continuous dynamics (differential equations) ∀ i x ( i ) ′ = d ( i ) , d ( i ) ′ = f ( ω ( i ) , d ( i )) x ( j ) Discrete dynamics (control decisions) c ∀ i ω ( i ) := if .. then 0 else 2 Structural dynamics x ( i ) (communication/coupling) c ( i ) := negotiate(i,j) Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 6 / 21

  2. Model for Distributed Hybrid Systems Q: How to model distributed hybrid systems A: Quantified Hybrid Programs Model (Distributed Hybrid Systems) Continuous dynamics x ( n ) (differential equations) ∀ i x ( i ) ′ = d ( i ) , d ( i ) ′ = f ( ω ( i ) , d ( i )) x ( j ) Discrete dynamics (control decisions) c ∀ i ω ( i ) := if .. then 0 else 2 Structural dynamics x ( i ) (communication/coupling) c ( i ) := negotiate(i,j) Dimensional dynamics (appearance) Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 6 / 21

  3. Model for Distributed Hybrid Systems Q: How to model distributed hybrid systems A: Quantified Hybrid Programs Model (Distributed Hybrid Systems) Continuous dynamics x ( n ) (differential equations) ∀ i x ( i ) ′ = d ( i ) , d ( i ) ′ = f ( ω ( i ) , d ( i )) x ( j ) Discrete dynamics (control decisions) c ∀ i ω ( i ) := if .. then 0 else 2 Structural dynamics x ( i ) (communication/coupling) c ( i ) := negotiate(i,j) Dimensional dynamics (appearance) n := new Aircraft Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 6 / 21

  4. Quantified Differential Dynamic Logic Qd L : Syntax Definition (Quantified hybrid program α ) ∀ i : C x ( i ) ′ = θ (quantified ODE) � ∀ i : C x ( i ) := θ (quantified assignment) jump & test ? χ (conditional execution) α ; β (seq. composition) � α ∪ β (nondet. choice) Kleene algebra α ∗ (nondet. repetition) Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 7 / 21

  5. Quantified Differential Dynamic Logic Qd L : Syntax Definition (Quantified hybrid program α ) ∀ i : C x ( i ) ′ = θ (quantified ODE) � ∀ i : C x ( i ) := θ (quantified assignment) jump & test ? χ (conditional execution) α ; β (seq. composition) � α ∪ β (nondet. choice) Kleene algebra α ∗ (nondet. repetition) DATC ≡ ( ctrl ; fly ) ∗ x ( n ) ctrl ≡ ∀ i : A ω ( i ) := if ∀ j : A far ( i , j ) then 0 else 2 x ( j ) fly ≡ ∀ i : A x ( i ) ′′ = d ( i ) , d ( i ) ′ = f ( ω ( i ) , d ( i )) c x ( i ) Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 7 / 21

  6. Quantified Differential Dynamic Logic Qd L : Syntax Definition (Quantified hybrid program α ) ∀ i : C x ( i ) ′ = θ (quantified ODE) � ∀ i : C x ( i ) := θ (quantified assignment) jump & test ? χ (conditional execution) α ; β (seq. composition) � α ∪ β (nondet. choice) Kleene algebra α ∗ (nondet. repetition) DATC ≡ ( appear ; ctrl ; fly ) ∗ appear ≡ n := new A ; ?( ∀ j : A far ( j , n )) x ( n ) ctrl ≡ ∀ i : A ω ( i ) := if ∀ j : A far ( i , j ) then 0 else 2 x ( j ) fly ≡ ∀ i : A x ( i ) ′′ = d ( i ) , d ( i ) ′ = f ( ω ( i ) , d ( i )) c x ( i ) Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 7 / 21

  7. Quantified Differential Dynamic Logic Qd L : Syntax Definition (Quantified hybrid program α ) ∀ i : C x ( i ) ′ = θ (quantified ODE) � ∀ i : C x ( i ) := θ (quantified assignment) jump & test ? χ (conditional execution) α ; β (seq. composition) � α ∪ β (nondet. choice) Kleene algebra α ∗ (nondet. repetition) DATC ≡ ( appear ; ctrl ; fly ) ∗ appear ≡ n := new A ; ?( ∀ j : A far ( j , n )) x ( n ) ctrl ≡ ∀ i : A ω ( i ) := if ∀ j : A far ( i , j ) then 0 else 2 x ( j ) fly ≡ ∀ i : A x ( i ) ′′ = d ( i ) , d ( i ) ′ = f ( ω ( i ) , d ( i )) c new A is definable! x ( i ) Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 7 / 21

  8. Quantified Differential Dynamic Logic Qd L : Syntax Definition (Quantified hybrid program α ) ∀ i : C x ( i ) ′ = θ (quantified ODE) � ∀ i : C x ( i ) := θ (quantified assignment) jump & test ? χ (conditional execution) α ; β (seq. composition) � α ∪ β (nondet. choice) Kleene algebra α ∗ (nondet. repetition) DATC ≡ ( appear ; ctrl ; fly ) ∗ appear ≡ n := new A ; ?( ∀ j : A far ( j , n )) x ( n ) ctrl ≡ ∀ i : A ω ( i ) := if ∀ j : A far ( i , j ) then 0 else 2 x ( j ) fly ≡ ∀ i : A x ( i ) ′′ = d ( i ) , d ( i ) ′ = f ( ω ( i ) , d ( i )) c x ( i ) Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 7 / 21

  9. Quantified Differential Dynamic Logic Qd L : Syntax Definition (Qd L Formula φ ) ¬ , ∧ , ∨ , → , ∀ x , ∃ x , = , ≤ , + , · ( R -first-order part) [ α ] φ, � α � φ (dynamic part) ∀ i , j : A far ( i , j ) → [( appear ; ctrl ; fly ) ∗ ] ∀ i , j : A ( i = j ∨ ( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) − x 2 ( j )) 2 ≥ p 2 ) x ( n ) x ( j ) c x ( i ) Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 7 / 21

  10. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Quantified hybrid program α : transition semantics ) ∀ i : C x ( i ) := θ v w Details x if w ( x )( v e ]) = v e i [ [ i ] i [ [ θ ] ] (for all e ) w and otherwise unchanged v t 0 Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 8 / 21

  11. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Quantified hybrid program α : transition semantics ) ∀ i : C x ( i ) ′ = θ v w Details x ϕ ( t ) d ϕ ( t ) e w i [ [ x ( i )] ] ( ζ ) = ϕ ( ζ ) e i [ [ θ ] ] (for all e ) d t v t ∀ i x ( i ) ′ = θ Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 8 / 21

  12. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Quantified hybrid program α : transition semantics ) α ; β v s w α β Details Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 8 / 21

  13. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Quantified hybrid program α : transition semantics ) α ; β v s w α β Details x s w v t Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 8 / 21

  14. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Quantified hybrid program α : transition semantics ) α ; β v s w α β Details x s v w t Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 8 / 21

  15. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Quantified hybrid program α : transition semantics ) α ∗ v s 1 s 2 s n w α α α Details Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 8 / 21

  16. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Quantified hybrid program α : transition semantics ) α ∗ v s 1 s 2 s n w α α α Details x v w t Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 8 / 21

  17. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Quantified hybrid program α : transition semantics ) w 1 α v α ∪ β β w 2 Details Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 8 / 21

  18. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Quantified hybrid program α : transition semantics ) w 1 α v α ∪ β β w 2 Details x v w 1 w 2 t Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 8 / 21

  19. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Quantified hybrid program α : transition semantics ) ? χ if v | = χ v Details x no change if v | = χ v otherwise no transition t 0 Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 8 / 21

  20. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Quantified hybrid program α : transition semantics ) if v �| = χ v Details x no change if v | = χ v otherwise no transition t 0 Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 8 / 21

  21. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Qd L Formula φ ) φ v φ [ α ] φ φ Details Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 9 / 21

  22. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Qd L Formula φ ) v φ � α � φ Details Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 9 / 21

  23. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Qd L Formula φ ) [ α ] φ α -span v Details Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 9 / 21

  24. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Qd L Formula φ ) [ α ] φ α -span v � β � φ β -span Details Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 9 / 21

  25. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Qd L Formula φ ) � β � [ α ]-span [ α ] φ α -span v � β � φ β -span Details Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 9 / 21

  26. Quantified Differential Dynamic Logic Qd L : Semantics Definition (Qd L Formula φ ) � β � [ α ]-span [ α ] φ α -span v � β � φ β -span Details compositional semantics ⇒ compositional calculus! Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 9 / 21

  27. Outline (Verification Approach) Motivation 1 Quantified Differential Dynamic Logic Qd L 2 Design Syntax Semantics Proof Calculus for Distributed Hybrid Systems 3 Compositional Verification Calculus Air Traffic Control Derivations and Differentiation Soundness and Completeness Conclusions 4 Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 9 / 21

  28. Proof Calculus for Quantified Differential Dynamic Logic ∀ i ( i = u → φ ( θ )) φ ([ ∀ i x ( i ) := θ ] x ( u )) φ ∀ i x ( i ) := θ v w Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 10 / 21

  29. Proof Calculus for Quantified Differential Dynamic Logic ∀ i ( i = [ ∀ i x ( i ) := θ ] u → φ ( θ )) φ ([ ∀ i x ( i ) := θ ] x ( u )) φ ∀ i x ( i ) := θ v w Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 10 / 21

  30. Proof Calculus for Quantified Differential Dynamic Logic ∀ i ( i = [ ∀ i x ( i ) := θ ] u → φ ( θ )) φ ([ ∀ i x ( i ) := θ ] x ( u )) φ ∀ i x ( i ) := θ v w ∀ i x ( i ) ′ = θ v w ∃ t ≥ 0 �∀ i S ( t ) � φ �∀ i x ( i ) ′ = θ � φ φ Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 10 / 21

  31. Proof Calculus for Quantified Differential Dynamic Logic ∀ i ( i = [ ∀ i x ( i ) := θ ] u → φ ( θ )) φ ([ ∀ i x ( i ) := θ ] x ( u )) φ ∀ i x ( i ) := θ v w ∀ i x ( i ) ′ = θ v w ∃ t ≥ 0 �∀ i S ( t ) � φ �∀ i x ( i ) ′ = θ � φ φ ∀ i S ( t ) Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 10 / 21

  32. Proof Calculus for Quantified Differential Dynamic Logic ∀ i ( i = [ ∀ i x ( i ) := θ ] u → φ ( θ )) φ ([ ∀ i x ( i ) := θ ] x ( u )) φ ∀ i x ( i ) := θ v w ∀ i x ( i ) ′ = θ v w ∃ t ≥ 0 �∀ i S ( t ) � φ �∀ i x ( i ) ′ = θ � φ φ ∀ i S ( t ) solve infinite-dimensional diff. eqn.? Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 10 / 21

  33. Proof Calculus for Quantified Differential Dynamic Logic compositional semantics ⇒ compositional rules! Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 11 / 21

  34. Proof Calculus for Quantified Differential Dynamic Logic w 1 φ α [ α ] φ ∧ [ β ] φ v α ∪ β [ α ∪ β ] φ β w 2 φ Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 11 / 21

  35. Proof Calculus for Quantified Differential Dynamic Logic w 1 φ α [ α ] φ ∧ [ β ] φ v α ∪ β [ α ∪ β ] φ β w 2 φ α ; β [ α ][ β ] φ v s w [ α ; β ] φ α β [ α ][ β ] φ [ β ] φ φ Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 11 / 21

  36. Proof Calculus for Quantified Differential Dynamic Logic w 1 φ α [ α ] φ ∧ [ β ] φ v α ∪ β [ α ∪ β ] φ β w 2 φ α ; β [ α ][ β ] φ v s w [ α ; β ] φ α β [ α ][ β ] φ [ β ] φ φ α ∗ φ ( φ → [ α ] φ ) φ φ φ → [ α ] φ [ α ∗ ] φ v w α α α Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 11 / 21

  37. Air Traffic Control Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 12 / 21

  38. Air Traffic Control Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 12 / 21

  39. Air Traffic Control Verification? looks correct Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 12 / 21

  40. Air Traffic Control Verification? looks correct NO! Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 12 / 21

  41. Air Traffic Control ς y 2 ̺ ω e x 2 d x 1 y 1  x ′  1 = − v 1 + v 2 cos ϑ + ω x 2 x ′ 2 = v 2 sin ϑ − ω x 1     ϑ ′ = ̟ − ω Verification? looks correct NO! Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 12 / 21

  42. Air Traffic Control ς y 2 ̺ ω e x 2 d x 1 y 1  x ′  1 = − v 1 + v 2 cos ϑ + ω x 2 x ′ 2 = v 2 sin ϑ − ω x 1     ϑ ′ = ̟ − ω Example (“Solving” differential equations) 1 � x 1 ( t ) = x 1 ω̟ cos t ω − v 2 ω cos t ω sin ϑ + v 2 ω cos t ω cos t ̟ sin ϑ − v 1 ̟ sin t ω ω̟ 1 − sin ϑ 2 sin t ω � + x 2 ω̟ sin t ω − v 2 ω cos ϑ cos t ̟ sin t ω − v 2 ω � + v 2 ω cos ϑ cos t ω sin t ̟ + v 2 ω sin ϑ sin t ω sin t ̟ . . . Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 12 / 21

  43. Air Traffic Control ς y 2 ̺ ω e x 2 d x 1 y 1  x ′  1 = − v 1 + v 2 cos ϑ + ω x 2 x ′ 2 = v 2 sin ϑ − ω x 1     ϑ ′ = ̟ − ω Example (“Solving” differential equations) 1 � ∀ t ≥ 0 x 1 ω̟ cos t ω − v 2 ω cos t ω sin ϑ + v 2 ω cos t ω cos t ̟ sin ϑ − v 1 ̟ sin t ω ω̟ 1 − sin ϑ 2 sin t ω � + x 2 ω̟ sin t ω − v 2 ω cos ϑ cos t ̟ sin t ω − v 2 ω � + v 2 ω cos ϑ cos t ω sin t ̟ + v 2 ω sin ϑ sin t ω sin t ̟ . . . Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 12 / 21

  44. Differential Invariants for Differential Equations Idea (Differential Invariant) Formula that remains true in the direction of the dynamics Andr´ e Platzer. Differential-algebraic dynamic logic for differential-algebraic programs. J. Log. Comput. , 35(1): 309–352, 2010. Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 13 / 21

  45. Differential Invariants for Differential Equations Idea (Differential Invariant) Formula that remains true in the direction of the dynamics Andr´ e Platzer. Differential-algebraic dynamic logic for differential-algebraic programs. J. Log. Comput. , 35(1): 309–352, 2010. Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 13 / 21

  46. Differential Invariants for Differential Equations Idea (Differential Invariant) Formula that remains true in the direction of the dynamics Andr´ e Platzer. Differential-algebraic dynamic logic for differential-algebraic programs. J. Log. Comput. , 35(1): 309–352, 2010. Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 13 / 21

  47. Differential Invariants for Differential Equations Idea (Differential Invariant) Formula that remains true in the direction of the dynamics R 2 but R ∞ ?? Andr´ e Platzer. Differential-algebraic dynamic logic for differential-algebraic programs. J. Log. Comput. , 35(1): 309–352, 2010. Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 13 / 21

  48. Differential Induction: Local Dynamics w/o Solutions Definition (Differential Invariant) F closed under total differentiation with respect to differential constraints ¬ F F Details ( χ → F ′ ) χ → F → [ x ′ = θ ∧ χ ] F Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 14 / 21

  49. Differential Induction: Local Dynamics w/o Solutions Definition (Differential Invariant) F closed under total differentiation with respect to differential constraints ¬ F F Details ( χ → F ′ ) χ → F → [ x ′ = θ ∧ χ ] F Total differential F ′ of formulas ? Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 14 / 21

  50. Quantified Differential Invariants Definition (Quantified Differential Invariant) Quantified formula F closed under total differentiation with respect to quantified differential constraints Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 15 / 21

  51. Derivations and Differentiation Definition (Syntactic total derivation D ) D ( r ) = 0 if r a number symbol D ( x ( i )) = x ( i ) ′ if x : C → R , C � = R D ( a + b ) = D ( a ) + D ( b ) D ( a · b ) = D ( a ) · b + a · D ( b ) D ( a / b ) = ( D ( a ) · b − a · D ( b )) / b 2 Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 16 / 21

  52. Derivations and Differentiation Definition (Syntactic total derivation D ) D ( r ) = 0 if r a number symbol D ( x ( i )) = x ( i ) ′ if x : C → R , C � = R D ( a + b ) = D ( a ) + D ( b ) D ( a · b ) = D ( a ) · b + a · D ( b ) D ( a / b ) = ( D ( a ) · b − a · D ( b )) / b 2 D ( a ≥ b ) ≡ D ( a ) ≥ D ( b ) accordingly for >, = D ( F ∧ G ) ≡ D ( F ) ∧ D ( G ) D ( ∀ i F ) ≡ ∀ i D ( F ) Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 16 / 21

  53. Derivations and Differentiation Definition (Syntactic total derivation D ) D ( r ) = 0 if r a number symbol D ( x ( i )) = x ( i ) ′ if x : C → R , C � = R D ( a + b ) = D ( a ) + D ( b ) D ( a · b ) = D ( a ) · b + a · D ( b ) D ( a / b ) = ( D ( a ) · b − a · D ( b )) / b 2 D ( a ≥ b ) ≡ D ( a ) ≥ D ( b ) accordingly for >, = D ( F ∧ G ) ≡ D ( F ) ∧ D ( G ) D ( ∀ i F ) ≡ ∀ i D ( F ) i = j ∨ ( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) − x 2 ( j )) 2 ≥ p 2 � � P ≡ ∀ i , j : A i ′ = j ′ ∧ 2( x 1 ( i ) − x 1 ( j ))( x 1 ( i ) ′ − x 1 ( j ) ′ ) � ⇒ D ( P ) ≡ ∀ i , j : A + 2( x 2 ( i ) − x 2 ( j ))( x 2 ( i ) ′ − x 2 ( j ) ′ ) ≥ 0 � Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 16 / 21

  54. Derivations and Differentiation Definition (Syntactic total derivation D ) D ( r ) = 0 if r a number symbol D ( x ( i )) = x ( i ) ′ if x : C → R , C � = R D ( a + b ) = D ( a ) + D ( b ) D ( a · b ) = D ( a ) · b + a · D ( b ) D ( a / b ) = ( D ( a ) · b − a · D ( b )) / b 2 D ( a ≥ b ) ≡ D ( a ) ≥ D ( b ) accordingly for >, = D ( F ∧ G ) ≡ D ( F ) ∧ D ( G ) D ( ∀ i F ) ≡ ∀ i D ( F ) i = j ∨ ( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) − x 2 ( j )) 2 ≥ p 2 � � P ≡ ∀ i , j : A i ′ = j ′ ∧ 2( x 1 ( i ) − x 1 ( j ))( x 1 ( i ) ′ − x 1 ( j ) ′ ) � ⇒ D ( P ) ≡ ∀ i , j : A + 2( x 2 ( i ) − x 2 ( j ))( x 2 ( i ) ′ − x 2 ( j ) ′ ) ≥ 0 � Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 16 / 21

  55. Derivations and Differentiation Syntactic derivation D ( · ) coincides with analytic differentiation: Lemma (Derivation lemma) Valuation is a differential homomorphism: for all flows ϕ all ζ ∈ [0 , r ] d ϕ ( t )[ [ θ ] ] ( ζ ) = ¯ ϕ ( ζ )[ [ D ( θ )] ] d t Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 17 / 21

  56. Derivations and Differentiation Syntactic derivation D ( · ) coincides with analytic differentiation: Lemma (Derivation lemma) Valuation is a differential homomorphism: for all flows ϕ all ζ ∈ [0 , r ] d ϕ ( t )[ [ θ ] ] ( ζ ) = ¯ ϕ ( ζ )[ [ D ( θ )] ] d t Locally understand QDE as quantified assignments: Lemma (Quantified differential substitution principle) = ∀ i : C f ( i ) ′ = θ ∧ χ , then ϕ | = υ = [ ∀ i : C f ( i ) ′ := θ ] υ for all υ . If ϕ | Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 17 / 21

  57. Derivations and Differentiation Syntactic derivation D ( · ) coincides with analytic differentiation: Lemma (Derivation lemma) Valuation is a differential homomorphism: for all flows ϕ all ζ ∈ [0 , r ] d ϕ ( t )[ [ θ ] ] ( ζ ) = ¯ ϕ ( ζ )[ [ D ( θ )] ] d t Locally understand QDE as quantified assignments: Lemma (Quantified differential substitution principle) = ∀ i : C f ( i ) ′ = θ ∧ χ , then ϕ | = υ = [ ∀ i : C f ( i ) ′ := θ ] υ for all υ . If ϕ | Theorem (Quantified Differential Invariant) χ → [ ∀ i : C f ( i ) ′ := θ ] D ( F ) ( QDI ) is sound F → [ ∀ i : C f ( i ) ′ = θ ∧ χ ] F Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 17 / 21

  58. A Simple Proof with Quantified Differential Invariants ∀ i : C 2 x ( i ) 3 ≥ 1 → [ ∀ i : C x ( i ) ′ = x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 2 x ( i ) 3 ≥ 1 Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 18 / 21

  59. A Simple Proof with Quantified Differential Invariants [ ∀ i : C x ( i ) ′ := x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 2( x ( i ) 3 ) ′ ≥ 0 ∀ i : C 2 x ( i ) 3 ≥ 1 → [ ∀ i : C x ( i ) ′ = x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 2 x ( i ) 3 ≥ 1 Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 18 / 21

  60. A Simple Proof with Quantified Differential Invariants [ ∀ i : C x ( i ) ′ := x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 6 x ( i ) 2 x ( i ) ′ ≥ 0 [ ∀ i : C x ( i ) ′ := x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 2( x ( i ) 3 ) ′ ≥ 0 ∀ i : C 2 x ( i ) 3 ≥ 1 → [ ∀ i : C x ( i ) ′ = x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 2 x ( i ) 3 ≥ 1 Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 18 / 21

  61. A Simple Proof with Quantified Differential Invariants ∀ i : C 6 x ( i ) 2 ( x ( i ) 2 + x ( i ) 4 + 2) ≥ 0 [ ∀ i : C x ( i ) ′ := x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 6 x ( i ) 2 x ( i ) ′ ≥ 0 [ ∀ i : C x ( i ) ′ := x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 2( x ( i ) 3 ) ′ ≥ 0 ∀ i : C 2 x ( i ) 3 ≥ 1 → [ ∀ i : C x ( i ) ′ = x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 2 x ( i ) 3 ≥ 1 Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 18 / 21

  62. A Simple Proof with Quantified Differential Invariants true ∀ i : C 6 x ( i ) 2 ( x ( i ) 2 + x ( i ) 4 + 2) ≥ 0 [ ∀ i : C x ( i ) ′ := x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 6 x ( i ) 2 x ( i ) ′ ≥ 0 [ ∀ i : C x ( i ) ′ := x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 2( x ( i ) 3 ) ′ ≥ 0 ∀ i : C 2 x ( i ) 3 ≥ 1 → [ ∀ i : C x ( i ) ′ = x ( i ) 2 + x ( i ) 4 + 2] ∀ i : C 2 x ( i ) 3 ≥ 1 Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 18 / 21

  63. Differential Induction for Aircraft Roundabouts [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y c x Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  64. Differential Induction for Aircraft Roundabouts i ′ = j ′ ∧ 2( x 1 ( i ) − x 1 ( j ))( x 1 ( i ) ′ − x 1 ( j ) ′ ) + 2( x 2 ( i ) − x 2 ( j ))( x 2 ( i ) ′ − x 2 ( j ) ′ ) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y c x Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  65. Differential Induction for Aircraft Roundabouts i ′ = j ′ ∧ 2( x 1 ( i ) − x 1 ( j ))( x 1 ( i ) ′ − x 1 ( j ) ′ ) + 2( x 2 ( i ) − x 2 ( j ))( x 2 ( i ) ′ − x 2 ( j ) ′ ) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y c x Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  66. Differential Induction for Aircraft Roundabouts 0 = 0 ∧ 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y c x Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  67. Differential Induction for Aircraft Roundabouts 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 0 = 0 ∧ 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y c x Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  68. Differential Induction for Aircraft Roundabouts 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 0 = 0 ∧ 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y e y − c x e x d − e d Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  69. Differential Induction for Aircraft Roundabouts 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 0 = 0 ∧ 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y e y − c x e x d − e d [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )] d 1 ( i ) − d 1 ( j ) = − ω ( x 2 ( i Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  70. Differential Induction for Aircraft Roundabouts 2( x 1 ( i ) − x 1 ( j ))( − ω ( x 2 ( i ) − x 2 ( j ))) + 2( x 2 ( i ) − x 2 ( j )) ω ( x 1 ( i ) − x 1 ( j )) ≥ 0 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 0 = 0 ∧ 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y e y − c x e x d − e d [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )] d 1 ( i ) − d 1 ( j ) = − ω ( x 2 ( i Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  71. Differential Induction for Aircraft Roundabouts 2( x 1 ( i ) − x 1 ( j ))( − ω ( x 2 ( i ) − x 2 ( j ))) + 2( x 2 ( i ) − x 2 ( j )) ω ( x 1 ( i ) − x 1 ( j )) ≥ 0 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 0 = 0 ∧ 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y e y − c x e x d − e d d 1 ( i ) ′ − d 1 ( j ) ′ = − ω ( x 2 ( i ) ′ − x 2 ( j ) ′ ) [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )] d 1 ( i ) − d 1 ( j ) = − ω ( x 2 ( i Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  72. Differential Induction for Aircraft Roundabouts 2( x 1 ( i ) − x 1 ( j ))( − ω ( x 2 ( i ) − x 2 ( j ))) + 2( x 2 ( i ) − x 2 ( j )) ω ( x 1 ( i ) − x 1 ( j )) ≥ 0 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 0 = 0 ∧ 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y e y − c x e x d − e d d 1 ( i ) ′ − d 1 ( j ) ′ = − ω ( x 2 ( i ) ′ − x 2 ( j ) ′ ) [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )] d 1 ( i ) − d 1 ( j ) = − ω ( x 2 ( i Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  73. Differential Induction for Aircraft Roundabouts 2( x 1 ( i ) − x 1 ( j ))( − ω ( x 2 ( i ) − x 2 ( j ))) + 2( x 2 ( i ) − x 2 ( j )) ω ( x 1 ( i ) − x 1 ( j )) ≥ 0 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 0 = 0 ∧ 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y e y − c x e x d − e d − ω d 2 ( i ) − − ω d 2 ( j ) = − ω ( d 2 ( i ) − d 2 ( j )) [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )] d 1 ( i ) − d 1 ( j ) = − ω ( x 2 ( i Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  74. Differential Induction for Aircraft Roundabouts 2( x 1 ( i ) − x 1 ( j ))( − ω ( x 2 ( i ) − x 2 ( j ))) + 2( x 2 ( i ) − x 2 ( j )) ω ( x 1 ( i ) − x 1 ( j )) ≥ 0 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 0 = 0 ∧ 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) y e y − c x e x d − e d − ω d 2 ( i ) + ω d 2 ( j ) = − ω ( d 2 ( i ) − d 2 ( j )) − ω d 2 ( i ) − − ω d 2 ( j ) = − ω ( d 2 ( i ) − d 2 ( j )) [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )] d 1 ( i ) − d 1 ( j ) = − ω ( x 2 ( i Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

  75. Differential Induction & Differential Cuts 2( x 1 ( i ) − x 1 ( j ))( − ω ( x 2 ( i ) − x 2 ( j ))) + 2( x 2 ( i ) − x 2 ( j )) ω ( x 1 ( i ) − x 1 ( j )) ≥ 0 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 0 = 0 ∧ 2( x 1 ( i ) − x 1 ( j ))( d 1 ( i ) − d 1 ( j )) + 2( x 2 ( i ) − x 2 ( j ))( d 2 ( i ) − d 2 ( j )) ≥ 0 [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )]( x 1 ( i ) − x 1 ( j )) 2 + ( x 2 ( i ) Proposition (Differential cut) F differential invariant of [ ∀ i x ( i ) ′ = θ ∧ H ] φ , then [ ∀ i x ( i ) ′ = θ ∧ H ] φ [ ∀ i x ( i ) ′ = θ ∧ H ∧ F ] φ iff − ω d 2 ( i ) + ω d 2 ( j ) = − ω ( d 2 ( i ) − d 2 ( j )) − ω d 2 ( i ) − − ω d 2 ( j ) = − ω ( d 2 ( i ) − d 2 ( j )) [ ∀ ix 1 ( i ) ′ = d 1 ( i ) , d 1 ( i ) ′ = − ω d 2 ( i ) , x 2 ( i ) ′ = d 2 ( i ) , d 2 ( i ) ′ = ω d 1 ( i )] d 1 ( i ) − d 1 ( j ) = − ω ( x 2 ( i Andr´ e Platzer (CMU) Quantified Differential Invariants HSCC 19 / 21

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