Logic & Philosophy of Science Colloquium

Reasoning about Virtual Entities II Although this will be a sequel to `Reasoning about Virtual Entities' the chief difficulty for listeners who missed the original will be that they will not have been provided with motivation. The talk will be self-contained, and devoted to the logical issues underlying the philosophical issues of the last talk. Congruence relations give rise to virtual (eliminable) entities. Talk about these things has to respect certain syntactic constraints: (can't ask: ``Is 3 a member of 5?") and these constraints emerge from the strategies for elimination. In this talk I shall examine what these constraints are by explaining in detail how they arise.