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.
Boolean concept structures. In each structure, eight objects differing in three binary dimensions are grouped into two categories of four elements. Each object is represented as a corner of a cube based on its combination of features, and the objects chosen for one category in each problem type are represented by dots.
