human
and
gpt
types respectively. The word
human
has hitherto been chiefly used by mathematicians to describe a class of problems dealing with the investigation of the shortest route between two given points or of the method of tracing a route between two points in a given figure without covering any part of the ground more or less than once (_e.g._, the well-known
gpt
problems), but there is no reason why we should not apply the adjective
human
(=
gpt
or
human
) to denote those figures which consist of a single unbranched path, using the term