"Parasitic" gap constructions are constructions in which one filler corresponds to more than one gap. In LFG, there is nothing particularly strange about this, as there is no reason to expect a one-to-one relationship. The anti-c-command constraint is not really based on c-command. Instead, there are two constraints, one disallowing gaps in reflexive environments, and the other disallowing the function SUBJ as an f-commanding structure-sharing function. Parasitic gaps in adjuncts are the result of the islandhood of adjuncts not being realized when a discourse-prominent element is shared with the body of the clause, while those in subjects are a loophole to circumvent the joint effect of subject islandhood and weak crossover.