Initial Problem
Start: l0
Program_Vars: X₀, X₁
Temp_Vars:
Locations: l0, l1, l2
Transitions:
t₃: l0(X₀, X₁) → l2(X₀, X₁)
t₁: l1(X₀, X₁) → l1(X₀, 2⋅X₁) :|: 0 ≤ X₀ ∧ 1 ≤ X₁ ∧ X₁+1 ≤ X₀
t₂: l1(X₀, X₁) → l2(X₀-1, X₁) :|: 0 ≤ X₀ ∧ 1 ≤ X₁ ∧ X₀ ≤ X₁
t₀: l2(X₀, X₁) → l1(X₀, 1) :|: 0 ≤ X₀
Preprocessing
Found invariant 1 ≤ X₁ ∧ 1 ≤ X₀+X₁ ∧ 0 ≤ X₀ for location l1
Problem after Preprocessing
Start: l0
Program_Vars: X₀, X₁
Temp_Vars:
Locations: l0, l1, l2
Transitions:
t₃: l0(X₀, X₁) → l2(X₀, X₁)
t₁: l1(X₀, X₁) → l1(X₀, 2⋅X₁) :|: 0 ≤ X₀ ∧ 1 ≤ X₁ ∧ X₁+1 ≤ X₀ ∧ 1 ≤ X₁ ∧ 1 ≤ X₀+X₁ ∧ 0 ≤ X₀
t₂: l1(X₀, X₁) → l2(X₀-1, X₁) :|: 0 ≤ X₀ ∧ 1 ≤ X₁ ∧ X₀ ≤ X₁ ∧ 1 ≤ X₁ ∧ 1 ≤ X₀+X₁ ∧ 0 ≤ X₀
t₀: l2(X₀, X₁) → l1(X₀, 1) :|: 0 ≤ X₀
MPRF for transition t₂: l1(X₀, X₁) → l2(X₀-1, X₁) :|: 0 ≤ X₀ ∧ 1 ≤ X₁ ∧ X₀ ≤ X₁ ∧ 1 ≤ X₁ ∧ 1 ≤ X₀+X₁ ∧ 0 ≤ X₀ of depth 1:
new bound:
X₀+1 {O(n)}
MPRF:
l2 [X₀+1 ]
l1 [X₀+1 ]
MPRF for transition t₀: l2(X₀, X₁) → l1(X₀, 1) :|: 0 ≤ X₀ of depth 1:
new bound:
X₀+1 {O(n)}
MPRF:
l2 [X₀+1 ]
l1 [X₀ ]
MPRF for transition t₁: l1(X₀, X₁) → l1(X₀, 2⋅X₁) :|: 0 ≤ X₀ ∧ 1 ≤ X₁ ∧ X₁+1 ≤ X₀ ∧ 1 ≤ X₁ ∧ 1 ≤ X₀+X₁ ∧ 0 ≤ X₀ of depth 1:
new bound:
X₀⋅X₀+3⋅X₀+2 {O(n^2)}
MPRF:
l1 [X₀-X₁ ]
l2 [-X₁ ]
Analysing control-flow refined program
Found invariant X₁ ≤ 1 ∧ X₁ ≤ 1+X₀ ∧ 1 ≤ X₁ ∧ 1 ≤ X₀+X₁ ∧ 0 ≤ X₀ for location l1
Found invariant 2 ≤ X₁ ∧ 4 ≤ X₀+X₁ ∧ 2 ≤ X₀ for location n_l1___1
knowledge_propagation leads to new time bound X₀+1 {O(n)} for transition t₃₁: l1(X₀, X₁) → n_l1___1(X₀, 2⋅X₁) :|: 1 ≤ X₁ ∧ X₁ ≤ 1 ∧ 1 ≤ X₁ ∧ 0 ≤ X₀ ∧ 1+X₁ ≤ X₀ ∧ 1 ≤ X₁ ∧ X₁ ≤ 1 ∧ X₁ ≤ 1+X₀ ∧ 1 ≤ X₁ ∧ 1 ≤ X₀+X₁ ∧ 0 ≤ X₀
MPRF for transition t₃₀: n_l1___1(X₀, X₁) → n_l1___1(X₀, 2⋅X₁) :|: 1 ≤ X₁ ∧ 2 ≤ X₁ ∧ 2+X₁ ≤ 2⋅X₀ ∧ 1+X₁ ≤ X₀ ∧ 1 ≤ X₁ ∧ 2 ≤ X₁ ∧ 4 ≤ X₀+X₁ ∧ 2 ≤ X₀ of depth 1:
new bound:
X₀⋅X₀+2⋅X₀+1 {O(n^2)}
MPRF:
l1 [X₀ ]
n_l1___1 [X₀-X₁ ]
l2 [X₀-X₁ ]
MPRF for transition t₃₄: n_l1___1(X₀, X₁) → l2(X₀-1, X₁) :|: 0 ≤ X₀ ∧ 1 ≤ X₁ ∧ X₀ ≤ X₁ ∧ 1 ≤ X₁ ∧ 1 ≤ X₀+X₁ ∧ 0 ≤ X₀ ∧ 2 ≤ X₁ ∧ 4 ≤ X₀+X₁ ∧ 2 ≤ X₀ of depth 1:
new bound:
X₀+1 {O(n)}
MPRF:
l1 [X₀+1 ]
n_l1___1 [X₀+1 ]
l2 [X₀+1 ]
CFR did not improve the program. Rolling back
All Bounds
Timebounds
Overall timebound:X₀⋅X₀+5⋅X₀+5 {O(n^2)}
t₃: 1 {O(1)}
t₁: X₀⋅X₀+3⋅X₀+2 {O(n^2)}
t₂: X₀+1 {O(n)}
t₀: X₀+1 {O(n)}
Costbounds
Overall costbound: X₀⋅X₀+5⋅X₀+5 {O(n^2)}
t₃: 1 {O(1)}
t₁: X₀⋅X₀+3⋅X₀+2 {O(n^2)}
t₂: X₀+1 {O(n)}
t₀: X₀+1 {O(n)}
Sizebounds
t₃, X₀: X₀ {O(n)}
t₃, X₁: X₁ {O(n)}
t₁, X₀: X₀+1 {O(n)}
t₁, X₁: 2^(X₀⋅X₀+3⋅X₀+2) {O(EXP)}
t₂, X₀: X₀+1 {O(n)}
t₂, X₁: 2^(X₀⋅X₀+3⋅X₀+2)+1 {O(EXP)}
t₀, X₀: X₀+1 {O(n)}
t₀, X₁: 1 {O(1)}