Prove that every k-linked graph G is (2k − 1)-connected











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So a graph is $k$-linked if $G$ has at least $2k$ vertices, and for $x_1,ldots,x_k,y_1,ldots,y_k$ that are 2k distinct vertices there are disjoint paths $P_1,ldots,P_k$ joining $x_i$ to $y_i$.



$G$ is $(2k-1)$-connected if size of $G$ is greater than $2k-1$ and $G$ has no separator of size less than $2k-1$.



I have tried proof by contradiction but seem to be stuck, I presume it is fairly easy and am getting frustrated that I cant figure it out??










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    Please use Latex/MathJax. Could you elaborate on your attempts so far?
    – Stockfish
    Nov 23 at 14:29










  • It seems reasonable to leave the title in plain ASCII here. I've added MathJax markup and $LaTeX$ syntax to the body. See this introduction to posting mathematical notation.
    – hardmath
    Nov 23 at 14:53















up vote
-2
down vote

favorite












So a graph is $k$-linked if $G$ has at least $2k$ vertices, and for $x_1,ldots,x_k,y_1,ldots,y_k$ that are 2k distinct vertices there are disjoint paths $P_1,ldots,P_k$ joining $x_i$ to $y_i$.



$G$ is $(2k-1)$-connected if size of $G$ is greater than $2k-1$ and $G$ has no separator of size less than $2k-1$.



I have tried proof by contradiction but seem to be stuck, I presume it is fairly easy and am getting frustrated that I cant figure it out??










share|cite|improve this question




















  • 1




    Please use Latex/MathJax. Could you elaborate on your attempts so far?
    – Stockfish
    Nov 23 at 14:29










  • It seems reasonable to leave the title in plain ASCII here. I've added MathJax markup and $LaTeX$ syntax to the body. See this introduction to posting mathematical notation.
    – hardmath
    Nov 23 at 14:53













up vote
-2
down vote

favorite









up vote
-2
down vote

favorite











So a graph is $k$-linked if $G$ has at least $2k$ vertices, and for $x_1,ldots,x_k,y_1,ldots,y_k$ that are 2k distinct vertices there are disjoint paths $P_1,ldots,P_k$ joining $x_i$ to $y_i$.



$G$ is $(2k-1)$-connected if size of $G$ is greater than $2k-1$ and $G$ has no separator of size less than $2k-1$.



I have tried proof by contradiction but seem to be stuck, I presume it is fairly easy and am getting frustrated that I cant figure it out??










share|cite|improve this question















So a graph is $k$-linked if $G$ has at least $2k$ vertices, and for $x_1,ldots,x_k,y_1,ldots,y_k$ that are 2k distinct vertices there are disjoint paths $P_1,ldots,P_k$ joining $x_i$ to $y_i$.



$G$ is $(2k-1)$-connected if size of $G$ is greater than $2k-1$ and $G$ has no separator of size less than $2k-1$.



I have tried proof by contradiction but seem to be stuck, I presume it is fairly easy and am getting frustrated that I cant figure it out??







graph-theory graph-connectivity






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edited Nov 23 at 14:51









hardmath

28.6k94994




28.6k94994










asked Nov 23 at 14:23









cxh

1




1








  • 1




    Please use Latex/MathJax. Could you elaborate on your attempts so far?
    – Stockfish
    Nov 23 at 14:29










  • It seems reasonable to leave the title in plain ASCII here. I've added MathJax markup and $LaTeX$ syntax to the body. See this introduction to posting mathematical notation.
    – hardmath
    Nov 23 at 14:53














  • 1




    Please use Latex/MathJax. Could you elaborate on your attempts so far?
    – Stockfish
    Nov 23 at 14:29










  • It seems reasonable to leave the title in plain ASCII here. I've added MathJax markup and $LaTeX$ syntax to the body. See this introduction to posting mathematical notation.
    – hardmath
    Nov 23 at 14:53








1




1




Please use Latex/MathJax. Could you elaborate on your attempts so far?
– Stockfish
Nov 23 at 14:29




Please use Latex/MathJax. Could you elaborate on your attempts so far?
– Stockfish
Nov 23 at 14:29












It seems reasonable to leave the title in plain ASCII here. I've added MathJax markup and $LaTeX$ syntax to the body. See this introduction to posting mathematical notation.
– hardmath
Nov 23 at 14:53




It seems reasonable to leave the title in plain ASCII here. I've added MathJax markup and $LaTeX$ syntax to the body. See this introduction to posting mathematical notation.
– hardmath
Nov 23 at 14:53















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