![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=8da2268e35b6b6daab9c47f71c4c8bf4.png\")
is the year and the output value ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=b1f02a70f7489dd3b8742e9e1c94d6d0.png\")
is the day of the week.The relation : The input value is the year and the output value is the day of the week.
Each value of ![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=8da2268e35b6b6daab9c47f71c4c8bf4.png\")
can be assigned to more than one ![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=b1f02a70f7489dd3b8742e9e1c94d6d0.png\")
-value because a given year corresponds to more than one day of the week.
Therefore, the relation is not a function.
\ \The relation is not a function.