Action a is applicable in state s if pre a ⊆ s; in that case, the outcome state is defined as s := (s∪add a ∪ e∈CEff a :cona⊆s add e )\(del a ∪ e∈CEff a :cona⊆s del e ).
s results from s by including the add lists of the action plus those effects whose condition holds in s, and afterwards removes the delete lists of the action and those effects.