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IMAGERY FOR OPEN‐WORLD SPATIAL PROBLEMS
Author(s) -
Faltings Boi,
Pu Pearl
Publication year - 1993
Publication title -
computational intelligence
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.353
H-Index - 52
eISSN - 1467-8640
pISSN - 0824-7935
DOI - 10.1111/j.1467-8640.1993.tb00237.x
Subject(s) - citation , library science , information retrieval , pearl , computer science , world wide web , geography , archaeology
In her paper ([4]), Janice Glasgow adresses many important advantages thatimagery models can oer over sentential models such as predicate logic. Inthis response, we point out another important advantage of imagery withrespect to the formulation of models.Consider the problem of reasoning about placing two-dimensional polygo-nal“blocks” inaspace, illustrated inFigure 1. Forpurposes such asplanning,knowledge about the blocks world is commonly formalized as rules which de-ne the legal operations. Rules are based on symbolic features, for example,a rule may state that:HOLDING(x,t)∧ CLEAR(y,t)∧ PUTON(x,y,t) ⇒ ON(x,y,t+1)meaning that executing the operation PUTON on x and y at time t willresult in x being on top of y at the following instant, under the conditionthat at time t, the manipulator was holding x and y was clear.However, as illustrated by Figure 1, such a rule may create an incorrectresult when other objects are present: placing B on top of A results in an1