IN4387 System Validation - Summary to refresh
concepts from the lectures
Timon Bestebreur (timonbestebreur.nl)
Dear student, thanks for checking out this summary! This is not a comprehensive
all-encompassing document with EVERYTHING YOU EVER NEED TO KNOW. It will
help you refresh your memory to be sharp when the test-taking begins. Practicing
with this material is essential, and the programming is something you cannot learn
by reading. You have to DO it to learn that. However, the end of this document does
contain some helpful code snippets that can help youlearn some important constructs
by heart.
Enjoy this course, since it is a lot of fun. Good luck with the exam!
Timon
Behavioral equivalences
LTS Labelled transition system
trace equivalence = same traces
weak trace equivalence = same traces, jumping over internal actions &
the internal actions do not even show up in the
trace
bisimilar = 1) For each state s there exists a state t with the
same transition that leads to a state that is also
bisimilar, 2) Terminal states are always bisimilar
strong bisimulation = same as bisimilar
branching bisimilarity = bisimilarity, where jumping over internal
actions to get to a state that you want to compare
is allowed. Note: You do need to reach ONE state
that satisfies ALL transitions. You cannot pick and
combine transitions reachable via tau transitions.
Divergence-preserving = bisimulation that preserves 𝜏 loops: Also the 𝜏
branching bisimulation loops need to match → If there is a 𝜏 loop in LTS
A, there also needs to be a 𝜏 loop in LTS B (and
the other way around)
rooted branching bisimilar = branching bisimilarity, and: for both transition
sytems it must hold that the initial state must have
exactly the same transitions, including 𝜏
transitions (if state 𝑠0 has a 𝜏 transition, 𝑡0 should
have it as well (and the other way around))
weak bisimilarity = branching bisimilar, and: 1) We don’t care
which branch is taken, as long as the same actions
can be done. 2) We skip infinite loops and don’t
compare those between the two LTS’s
1
concepts from the lectures
Timon Bestebreur (timonbestebreur.nl)
Dear student, thanks for checking out this summary! This is not a comprehensive
all-encompassing document with EVERYTHING YOU EVER NEED TO KNOW. It will
help you refresh your memory to be sharp when the test-taking begins. Practicing
with this material is essential, and the programming is something you cannot learn
by reading. You have to DO it to learn that. However, the end of this document does
contain some helpful code snippets that can help youlearn some important constructs
by heart.
Enjoy this course, since it is a lot of fun. Good luck with the exam!
Timon
Behavioral equivalences
LTS Labelled transition system
trace equivalence = same traces
weak trace equivalence = same traces, jumping over internal actions &
the internal actions do not even show up in the
trace
bisimilar = 1) For each state s there exists a state t with the
same transition that leads to a state that is also
bisimilar, 2) Terminal states are always bisimilar
strong bisimulation = same as bisimilar
branching bisimilarity = bisimilarity, where jumping over internal
actions to get to a state that you want to compare
is allowed. Note: You do need to reach ONE state
that satisfies ALL transitions. You cannot pick and
combine transitions reachable via tau transitions.
Divergence-preserving = bisimulation that preserves 𝜏 loops: Also the 𝜏
branching bisimulation loops need to match → If there is a 𝜏 loop in LTS
A, there also needs to be a 𝜏 loop in LTS B (and
the other way around)
rooted branching bisimilar = branching bisimilarity, and: for both transition
sytems it must hold that the initial state must have
exactly the same transitions, including 𝜏
transitions (if state 𝑠0 has a 𝜏 transition, 𝑡0 should
have it as well (and the other way around))
weak bisimilarity = branching bisimilar, and: 1) We don’t care
which branch is taken, as long as the same actions
can be done. 2) We skip infinite loops and don’t
compare those between the two LTS’s
1
