Fig 1. Decision tree to determine the state of a person or object x that exists at t1: Yi is a possible continuer i of x at t2 (adapted from Nozick, 1981).
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.