Robotics Reference
In-Depth Information
at(airport, county)
Meaning: The airport is in that particular county.
2. The Advice Taker also needed to know that, if A is at B and B is
at C then A is at C. So if I am at my desk and my desk is at home
then I am at home. In logic this relationship is expressed, using the
“implies” symbol
⊃
thus:
at(x,y), at(y,z)
⊃
at(x,z)
3. There are two rules needed by the Advice Taker concerning the
feasibility of walking and driving. They are:
walkable(x), at(y,x), at(z,x), at(I,y)
⊃
can(go(y,z,walking)
and
drivable(x), at(y,x), at(z,x), at(car,y), at(I,car)
can(go(y,z,driving)
Meaning
: The first of these rules means that if the journey to
x is walkable [indicated by
walkable(x)
], and if y is at x [indi-
cated by
at(y,x)
], and if z is at x [indicated by
at(z,x)
], and if I
am at y [indicated by
at(I,y)
], then all of these being true implies
[shown by the
⊃
symbol] that I can walk from y to z [indicated by
can(go(y,z,walking) ]. This is easy to understand—I am at y and
the journey to x is walkable so I can walk to x, and since z is at x,
by walking to x I also walk to where z is located.
The second of these rules has a comparable meaning, relating to
driving from y to z.
The system also needs two specific facts:
walkable(home)
Meaning
: The journey to home is walkable.
drivable(county)
Meaning
: Anywhere in the county is drivable.
4. Next there is a rule concerned with the properties of going:
did(go(x, y, z))
at(I,y)
Meaning: I did go from x to y by method z implies that I am now
at y.
⊃
5. And the problem to be solved is expressed by:
