<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31333713</termId><termName>concave</termName><termType>PT</termType><termNote><![CDATA[ Of a plane figure, a solid or a set of points that is not convex, for example, hollowed out like the inner curve of a circle or sphere. An arc of a curve is concave toward a point or line if every segment of the arc cut off by a secant lies on the opposite side of the secant from the point or line. A concave polygon always has an interior angle greater than 180 degrees. ]]></termNote><termCreatedDate>2026-03-30 20:29:55</termCreatedDate><relation><relationType>BT</relationType><termId>31311816</termId><termName>curved</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>31311890</termId><termName>dished</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>31333714</termId><termName>convex</termName><termType>PT</termType></relation></term>  </Zthes>