CTL* Semantics
CS 586
E: Exists a path
M, s | E (red)
s
NOT a model of
E: Exists a path
M, s | E (red)
s
A: All paths
M, s | A (red)
s
NOT a model of
A: All paths
M, s | A (red)
s
F: Eventually
M, s | F (red)
s
EF: Along some path, eventually
M, s | EF (red)
s
NOT a well-formed problem
AF: Along every path, eventually
M, s | AF (red)
s
NOT a model of
AF: Along every path, eventually
M, s | AF (red)
s
EGAF
M, s | EGAF (red)
s
there exists a path,
on which it is always
true that…
EGAF
M, s | EGAF (red)
there exists a path,
on which it is always
true that…
For all paths,
eventually red.
s
EGAF
M, s | EGAF (red)
there exists a path,
on which it is always
true that…
For all paths,
eventually red.
s
always means true for
all states on the path.
Get AF red for s.
EGAF
M, s | EGAF (red)
there exists a path,
on which it is always
true that…
For all paths,
eventually red.
s
always means true for
all states on the path.
Get AF red for s.
EGAF
M, s | EGAF (red)
there exists a path,
on which it is always
true that…
For all paths,
eventually red.
s
t
always means true for
all states on the path.
Get AF red for s.
Get AF red for t.
EGAF
M, s | EGAF (red)
there exists a path,
on which it is always
true that…
For all paths,
eventually red.
s
t
u
always means true for
all states on the path.
Get AF red for s.
Get AF red for t.
Get AF red for u.
EGAF
M, s | EGAF (red)
there exists a path,
on which it is always
true that…
For all paths,
eventually red.
s
t
u
v
always means true for
all states on the path.
Get AF red for s.
Get AF red for t.
Get AF red for u.
Get AF red for v.
s
Some Examples
• It always gets cloudy before it rains
• Bad things never happen
• Its possible to have your cake and eat it
too.
• I will eventually grade your homework