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Constraint Satisfaction. Agenda. Constraint Satisfaction Overview Thagard, 1989 Golstone & Rogosky, 2002. Constraint Satisfaction. The goal is to discover a solution to a problem that satisfies a set of constraints that are not intrinsic to the problem in general. Constraint Satisfaction.
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Agenda • Constraint Satisfaction Overview • Thagard, 1989 • Golstone & Rogosky, 2002
Constraint Satisfaction • The goal is to discover a solution to a problem that satisfies a set of constraints that are not intrinsic to the problem in general.
Constraint Satisfaction • The main benefit of viewing a problem as one of constraint satisfaction is computational. • In particular, less “search” is required.
Cryptarithemetic Problem SEND +MORE ------------ MONEY Rich & Knight, 1991 Example
Cryptarithemetic Problem • SEND + MORE = MONEY • Goal: To map letters to numbers in such a way that the initial constraints are satisfied.
Cryptarithemetic Problem M = 1 S = 8 or 9 O = 0 or 1 O = 0 N = E or E + 1 N = E + 1 C2 = 1 N+R > 8 E 9 SEND +MORE ----------- MONEY E=2 N = 3 R = 8 or 9 2 + D = Y or 2 + D = 10 + Y C1=0 C1=1 2 + D = Y N + R = 10 + E R = 9 S = 8 2 + D = 10 + Y D = 8 + Y D = 8 or 9 D = 8 D = 9 X X Y = 0 Y = 1