Let K(2,3) have bipartition B⋃W where B={a,b} and W={x,y,z}











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Why in a spanning tree of K(2,3) there must be precisely one of the vertices of {x,y,z} joined to both "a" and "b" ?










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    Why in a spanning tree of K(2,3) there must be precisely one of the vertices of {x,y,z} joined to both "a" and "b" ?










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      Why in a spanning tree of K(2,3) there must be precisely one of the vertices of {x,y,z} joined to both "a" and "b" ?










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      Why in a spanning tree of K(2,3) there must be precisely one of the vertices of {x,y,z} joined to both "a" and "b" ?







      graph-theory bipartite-graph






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      asked Nov 16 at 11:19









      Yahya

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          A spanning tree contains all vertices, but there is no edge between $a$ and $b$, so at least one vertex of $W$ must be connected to both.

          If they were connected to 2 vertices from $W$, it would contain a circle.






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            1 Answer
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            active

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            up vote
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            down vote



            accepted










            A spanning tree contains all vertices, but there is no edge between $a$ and $b$, so at least one vertex of $W$ must be connected to both.

            If they were connected to 2 vertices from $W$, it would contain a circle.






            share|cite|improve this answer

























              up vote
              0
              down vote



              accepted










              A spanning tree contains all vertices, but there is no edge between $a$ and $b$, so at least one vertex of $W$ must be connected to both.

              If they were connected to 2 vertices from $W$, it would contain a circle.






              share|cite|improve this answer























                up vote
                0
                down vote



                accepted







                up vote
                0
                down vote



                accepted






                A spanning tree contains all vertices, but there is no edge between $a$ and $b$, so at least one vertex of $W$ must be connected to both.

                If they were connected to 2 vertices from $W$, it would contain a circle.






                share|cite|improve this answer












                A spanning tree contains all vertices, but there is no edge between $a$ and $b$, so at least one vertex of $W$ must be connected to both.

                If they were connected to 2 vertices from $W$, it would contain a circle.







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                answered Nov 16 at 11:29









                Berci

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