1. Viewgraphs for Semantics

2. Strategy: From C1 to T o1:C1 o2:C2 declared type of o2 is C3=>C2 e
go down e iff C1 <=.C C3 =>.(<=.C.=>)*.<=) T

3. z
Strategy
S -> T x X1 Y1 Z1 y S X2 Y2 Z2 T t X3 Y3 Z3 x y z t
s1:S
x31:X3
y31:Y3
z31:Z3
t1:T
go down e iff S <=.C C3 =>.(<=.C.=>)*.<=) T

4. z
Strategy
S -> T x X1 Y1 Z1 y S X2 Y2 Z2 T t X3 Y3 Z3 x y z t
s1:S
x31:X3
y31:Y3
z31:Z3
t1:T
go down e iff S <=.C X1 =>.(<=.C.=>)*.<=) T

5. z
Strategy
S -> T x X1 Y1 Z1 y S X2 Y2 Z2 T t X3 Y3 Z3 x y z t
s1:S
x31:X3
y31:Y3
z31:Z3
t1:T
<=,=>
not
used
go down e iff S <=.C X1 =>.(<=.C.=><=.C.=><=.C=>).<=) T

6. Example class dictionary strategy A -> T T -> D 0..1 X 0..1 B D
A = [“x” X] [“r” R].
B = [“b” B] D.
R = S.
S = [“t” T] C
C = D.
X = B.
T = R.
D = .
strategy
Example
A -> T
T -> D
0..1 X
0..1 B D A C
0..1 :D :C R S T :A
0..1
class
graph
object
graph “r” :R :S

7. Example class dictionary strategy A -> T T -> D
A = [“x” X] [“r” R].
B = [“b” B] D.
R = S.
S = [“t” T] C
C = D.
X = B.
T = R.
D = .
strategy
Example
A -> T
T -> D
POSS(A,T,a1) = 1 edge
POSS(R,T,r1) = 1 edge
POSS(S,T,s1) = 0 edges
0..1 X
0..1 B D A C
0..1 :D :C R S T
a1:A
0..1
class
graph
object
graph “r”
r1:R
s1:S

8. Example class dictionary strategy A -> T T -> D
A = [“x” X] [“r” R].
B = [“b” B] D.
R = S.
S = [“t” T] C
C = D.
X = B.
T = R.
D = .
strategy
Example
A -> T
T -> D
POSS(A,T,a1) = 1 edge
POSS(R,T,r1) = 1 edge
POSS(S,T,s1) = 1 edge
0..1 X
0..1 B D A C
c2:C
d2:D
0..1 :D
c1:C R S T
a1:A
0..1
class
graph
r1:R
s1:S
t1:T
r2:R

9. Example 1 Only node paths shown for space reasons OG : A X R X C
strategy:
{A -> B
B -> C}
Object graph
Strategy s t :A A B C
x1:X
class graph S
e1:Empty :R R A
x2:X
Empty B x x c
c1:C b X
c2:C
OG : A X R X C
OG’: A X B X C
SG : A B C
(CG: A X Bopt B X C)
BOpt c
c3:C C

10. Example 1A Only node paths shown for space reasons early termination
strategy:
{A -> S
S -> C}
Object graph
early
termination
Strategy s t :A A S C
x1:X
class graph S
e1:Empty :R R A
x2:X
Empty B x x c
c1:C b X
c2:C
OG : A X R X
OG’: A X B X
SG : A B
(CG: A X Bopt B X)
BOpt c
c3:C C

11. Example 2 S = from BusRoute through Bus to Person busStops BusRoute
BusStopList
buses
0..*
NGasPowered
BusStop
BusList
waiting
0..*
passengers
Bus
PersonList
Person
0..*
DieselPowered

12. Example 2 OG : BR BL DP PL P OG’: BR BL B PL P SG : BR B P
Only node paths shown for space reasons
Route1:BusRoute
BusList
buses
busStops
:BusStopList
Bus15:DieselPowered
passengers
CentralSquare:BusStop
waiting
:PersonList
:PersonList
Joan:Person
Paul:Person
Seema:Person
Eric:Person
S = from BusRoute through Bus to Person

13. Example 3 OG : BR BL OG’: BR BL SG : BR
Only node paths shown for space reasons
early
termination
Route1:BusRoute
BusList
buses
busStops
:BusStopList
Bus15:DieselPowered
passengers
CentralSquare:BusStop
waiting
:PersonList
:PersonList
Joan:Person
Paul:Person
Seema:Person
Eric:Person
S = from BusRoute via NGasPowered to Person