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Links and Open Conditions

A link represents a causal dependency in the plan, specifying how a condition Cond is established by an effect Eff, which has Cond as a postcondition. Eff has secondary preconditions SecPre and is a result of step Step. The link supports the step SupStep or effect SupEff through the condition Cond which is one of:

A link is unsafe in a contingency Conting in which it is required if there is a clobbering effect ClobberEff with postcondition ClobberCond (the clobbering condition) resulting from step ClobberStep such that:

An open condition (an unachieved subgoal) is represented in Cassandra as an incomplete link, i.e., a link missing the information about the effect that establishes it.

Louise Pryor <>;
Last modified: Wed May 1 11:27:38 1996