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Oct 23, 2018 at 16:52 review Suggested edits
Oct 23, 2018 at 17:04
S Dec 19, 2015 at 16:26 history suggested Jan Hrcek CC BY-SA 3.0
Fix typo and improve wording
Dec 19, 2015 at 16:14 review Suggested edits
S Dec 19, 2015 at 16:26
Nov 9, 2014 at 13:43 comment added patang ah ..seems to be clear now...thanks.
Nov 9, 2014 at 13:38 comment added Peter Probably, it is meant that BOTH endpoints must belong to $U$, then everything is all right. Otherwise, the formulation would probably be : with at least one endpoint in $U$.
Nov 9, 2014 at 13:37 comment added patang yes I meant that like in this case ,the edge maynot belong in $H$ but has an endpoint in it...
Nov 9, 2014 at 13:35 comment added Peter Ah, now I see what you mean. The edge $2-4$ has an endpoint in $U$, is this the problem ?
Nov 9, 2014 at 13:33 comment added Peter Perhaps, an example helps : Suppose, the edges are $1-2,1-3,2-4,2-5,3-5$ and $U=${$1,2,3$}. The edges between the vertices in $U$ are $1-2,1-3$, so $H$ contains exactly these edges. The edges $2-4,2-5,3-5$ do not occur in $H$ because the vertices $4,5$ do not belong to $U$.
Nov 9, 2014 at 13:27 comment added patang the definition of your answer is understandable ,but I can't understand the one given in the question....what's relation between both of them...please help it seems to be confusing..
Nov 9, 2014 at 13:17 comment added Peter You mean the vertices ? They do not need to be adjacent in $G$, but if they are not, they are also not adjacent in $H$. To make it simpler : The edges with endpoints in $U$ are the edges remaining, if all vertices but those in $U$ are deleted.
Nov 9, 2014 at 13:13 comment added patang but as it says:"If F consists of all edges of G which have endpoints in U" ,where does it says that that edges are adjacent..
Nov 9, 2014 at 13:09 comment added Peter No, $U$ is the (in general proper) subset of $V$ and the vertex set in $H$ is only $U$, not $V$.
Nov 9, 2014 at 13:06 comment added patang in definition of induced subgraph as given in question it is:"If $F$ consists of all edges of $G$ which have endpoints in $U$ ,then $H$ is called induced subgraph of $G$ and is denoted by $G_U$." .. shouldn't it be $V$ insetad of $U$ ...
Nov 9, 2014 at 12:23 comment added Peter The edges of the REMAINING vertices are not allowed to be deleted, but deleting a vertex, of course, deletes the edges ending in this vertex.
Nov 9, 2014 at 12:20 comment added Peter The edges incident with a vertex are simply the edges having the vertex as an endpoint.
Nov 9, 2014 at 12:20 comment added patang @but I don't understand the meaning of incident edges in: "(and with them all the incident edges)but no more edges"....Please help..
Nov 9, 2014 at 12:18 comment added Peter No, the vertices are deleted, the vertex-set of H is, in general, a proper subset of V.
Nov 9, 2014 at 12:14 comment added patang but shouldn't the last line be :"an induced subgraph cannot be constructed by deleting vertices"
Nov 9, 2014 at 12:07 vote accept patang
Nov 9, 2014 at 12:03 history answered Peter CC BY-SA 3.0