A coordinate formula including: an x coordinate formula to indicate an x coordinate with 1-3 angles as a variable; a yz addition coordinate formula which indicates an addition value adding a z coordinate to a y coordinate; and a yz substraction coordinate formula which indicates a substraction value to substract the z coordinate from the y coordinate, is solved. 第1〜第3角度を変数としてx座標を表すx座標式と、y座標にz座標を加算した加算値を表すyz加算座標式と、y座標からz座標を減算した減算値を表すyz減算座標式とを含む座標式を解く。 - 特許庁