porism
不定設題;系論
Po·rism n.
1. Geom. A proposition affirming the possibility of finding such conditions as will render a certain determinate problem indeterminate or capable of innumerable solutions.
2. Gr. Geom. A corollary.
Note: ☞ Three books of porisms of Euclid have been lost, but several attempts to determine the nature of these propositions and to restore them have been made by modern geometers.
◄ ►