| 释义 |
polytomy|pəˈlɪtəmɪ|
[f. Gr. πολυ-, poly- + -τοµια, f. -τοµος cut. Cf. F. polytomie.]
The condition or character of being polytomous. (Distinguished from dichotomy and trichotomy.)
1. Bot. Division into several (more than two) branches at the same point.
1875Bennett & Dyer Sachs' Bot. 148 Dichotomy (rarely Polytomy)..is caused by the cessation of the previous increase in length of a member at the apex, and by two (or more) new apices arising at the apical surface close to one another, which..develope in diverging directions.
2. Logic. Division into several (usually, more than three) members.
a1856W. Hamilton Lect. Metaphysics & Logic (1860) IV. xxv. 23 If a division has only two members, it is called a dichotomy..; if three, a trichotomy..; if four, a tetrachotomy; if many, a polytomy, &c. 1864Bowen Logic iv. 101 Division into many members may be called a polytomy. 1867Atwater Logic 71 A division in three members is called a Trichotomy: into many members, a Polytomy. |