Predicate Metric Tense Logic for ‘Now’ and ‘Then’

Abstract

In a number of publications A.N. Prior considered the use of what he called ‘metric tense logic’. This is a tense logic in which the past and future operators P and F have an index representing a temporal distance, so that Pnα means that α was true n-much ago, and Fnα means that α will be true n-much hence. The paper investigates the use of metric predicate tense logic in formalising phenomena ormally treated by such devices as multiple indexing or quantification over times.