document.write( "Question 475379: prove that every path is gracefull. \n" ); document.write( "
Algebra.Com's Answer #326408 by richard1234(7193)\"\" \"About 
You can put this solution on YOUR website!
Label a path with three vertices:\r
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\n" ); document.write( "\n" ); document.write( "1--3--2\r
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\n" ); document.write( "\n" ); document.write( "A path with four vertices:\r
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\n" ); document.write( "\n" ); document.write( "1--4--2--3\r
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\n" ); document.write( "\n" ); document.write( "A path with five vertices:\r
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\n" ); document.write( "\n" ); document.write( "1--5--2--4--3\r
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\n" ); document.write( "\n" ); document.write( "In general, label an n-sided graph with the numbers 1, n, 2, n-1, 3, n-2,..., in which the differences between consecutive nodes are n-1, n-2, ..., 1, hence, graceful.\r
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\n" ); document.write( "\n" ); document.write( "The following website gives more information about graceful graphs:
\n" ); document.write( "http://mathworld.wolfram.com/GracefulGraph.html
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