Abstract
The systematic assumption of faithfulness violations in Optimality Theory implies an infinite space of candidates. Under the methodological principle of trying to explain as much possible through constraint interaction, control over this infinite space should be exerted by the constraints. Assuming the subsumption-based candidate definition of OT-LFG, the candidate space is indeed sufficiently structured to facilitate computational processing according to this principle. However, the parsing direction in the standard production-based optimization model is not subject to optimization, so for the parsing task, a decidability issue arises. Adopting a bidirectional optimization model is one way of solving this problem, but the required strong concept of bidirectional optimization may not be linguistically desirable. Other possible conclusions are discussed briefly.