if彐t∈T,a(t)=s∧β(t)=s′, we say s→s,we define the generalized transition relation C SX A× S such that oIfs→s,s oIfs→S’,S′→S", we say s→S" Let A =<S,So, T,a, B> be a Ts, we say S is reachable if s∈S,So∈S,S0-→S◼ 𝑖𝑓 ∃ 𝑡 ∈ 𝑇, 𝛼 𝑡 = 𝑠 ⋀𝛽 𝑡 = 𝑠 ′ ,we say s → 𝑠 ′ , we define the generalized transition relation ↠⊆ S × A × S such that  If s → 𝑠 ′ , s ↠ 𝑠 ′  If s ↠ 𝑠 ′ , s ′ ↠ 𝑠 ′′ , 𝑤𝑒 𝑠𝑎𝑦 𝑠 ↠ 𝑠 ′′ ◼ Let 𝒜 =< 𝑆, 𝑆0 ,𝑇, 𝛼, 𝛽 > be a TS, we say s is reachable if 𝑠 ∈ 𝑆, 𝑠0 ∈ 𝑆0 , 𝑠0 ↠ 𝑠