Suppose that the UR /cost us/ comes with the three candidate SRs [cost.us OT → (/cost.me/, [cos.me]) holds relative to the OT typology generated by constraints C 1 , C 2 , C 3 in the sense of definition 1: every ranking of the three constraints which succeeds on the antecedent mapping (/cost.us/, [cos.us]) also succeeds on the consequent mapping (/cost.me/, [cos.me]).
t/d deletion before a vowel entails deletion before a consonant.