Information Technology Reference
In-Depth Information
input
C
:
state constraint;
I
:
influence information;
output
R
:
set of causal relationships;
begin
let
R
=
fg
;
let
C
1
^ ::: ^ C
n
be the minimal CNF of
C
;
for all
i
=1
to
n
do
let
F
1
_ ::: _ F
m
=
C
i
;
for all
j
=1
to
m
do
for all
k
=1
to
m; k 6
=
j
do
let
=
^
:F
l
;
l
=1
;:::;m
l
6
=
j; l
6
=
k
case
F
j
is
`
j
:
case
F
k
is
`
k
:
let
r
=
:`
j
causes
`
k
if
;
case
F
k
is
8x
k
:`
k
[
x
k
]
: let
r
=
:`
j
causes
`
k
[
x
k
]if
;
case
F
k
is
9x
k
:`
k
[
x
k
]
:
let
r
=
:`
j
causes
`
k
[
x
k
]if
8x
k
: :`
k
[
x
k
]
^
case
F
j
is
8x
j
:`
j
[
x
j
]
:
case
F
k
is
`
k
:
let
r
=
:`
j
[
x
j
] causes
`
k
if
;
case
F
k
is
8x
k
:`
k
[
x
k
]
: let
r
=
:`
j
[
x
j
] causes
`
k
[
x
k
]if
;
case
F
k
is
9x
k
:`
k
[
x
k
]
:
let
r
=
:`
j
[
x
j
] causes
`
k
[
x
k
]if
8x
k
: :`
k
[
x
k
]
^
case
F
j
is
9x
j
:`
j
[
x
j
]
:
case
F
k
is
`
k
:
let
r
=
:`
j
[
x
j
] causes
`
k
if
8x
j
: :`
j
[
x
j
]
^
;
case
F
k
is
8x
k
:`
k
[
x
k
]
:
let
r
=
:`
j
[
x
j
] causes
`
k
[
x
k
]if
8x
j
: :`
j
[
x
j
]
^
;
case
F
k
is
9x
k
:`
k
[
x
k
]
:
l
et
r
=
:`
j
[
x
j
] causes
`
k
[
x
k
]if
8x
j
: :`
j
[
x
j
]
^8x
k
: :`
k
[
x
k
]
^
if
(
k`
j
[
x
j
]
k; k`
k
[
x
k
]
k
)
2I
then
let
R
=
R[frg
end-for
end-for
end
Figure 2.7.
An extended procedure for the automatic extraction of causal rela-
tionships.
may be used as indirect eect in a causal relationship whose context includes
8x: :`
[
x
]. On this basis, an extended algorithm for automatic generation of
causal relationships is depicted in Fig. 2.7.
Example 2.5.4.
Consider state constraint
C
=
light
8x:
up
(
x
), ex-
pressing the serial connection of all involved switches and a light bulb. Let
I
=
f
(
(
x
)
;
)
g
, then our extended algorithm traces as follows:
up
light
