Amalgam: различия между версиями

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(Создана новая страница размером '''Amalgam''' --- амальгама. Given two plane trees <math>T_{1}</math> and <math>T_{2}</math>, with the same number of leaves an...)
 
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'''Amalgam''' --- амальгама.  
'''Amalgam''' — ''[[амальгама]].''


Given two plane trees <math>T_{1}</math> and <math>T_{2}</math>,
Given two plane [[tree|trees]] <math>\,T_{1}</math> and <math>\,T_{2}</math>,
with the same number of leaves and without degree 2
with the same number of [[leaf|leaves]] and without [[degree of a vertex|degree 2 vertices]], and a bijection <math>\varphi</math> between their
vertices, and a bijection <math>\varphi</math> between their
leaf sets which preserves their order on the plane.
leaf sets which preserves their order on the plane.
The ''' amalgam''' <math>A =
The '''amalgam''' <math>A =
{\mathcal A}(T_{1},T_{2}, \varphi)</math> is the union of the corresponding ''Halin graphs'' <math>{\mathcal H}(T_{1})</math> and <math>{\mathcal H}(T_{2})</math> in which the
{\mathcal A}(T_{1},T_{2}, \varphi)</math> is the union of the corresponding ''[[Halin graph|Halin graphs]]'' <math>{\mathcal H}(T_{1})</math> and <math>{\mathcal H}(T_{2})</math> in which the
leaf vertices <math>v</math> and <math>\varphi(v)</math> are identified.
leaf vertices <math>\,v</math> and <math>\varphi(v)</math> are identified.

Текущая версия от 12:42, 25 ноября 2011

Amalgamамальгама.

Given two plane trees [math]\displaystyle{ \,T_{1} }[/math] and [math]\displaystyle{ \,T_{2} }[/math], with the same number of leaves and without degree 2 vertices, and a bijection [math]\displaystyle{ \varphi }[/math] between their leaf sets which preserves their order on the plane. The amalgam [math]\displaystyle{ A = {\mathcal A}(T_{1},T_{2}, \varphi) }[/math] is the union of the corresponding Halin graphs [math]\displaystyle{ {\mathcal H}(T_{1}) }[/math] and [math]\displaystyle{ {\mathcal H}(T_{2}) }[/math] in which the leaf vertices [math]\displaystyle{ \,v }[/math] and [math]\displaystyle{ \varphi(v) }[/math] are identified.