Ceiling[Infinity] == Infinity
Cell[BoxData[RowBox[List[RowBox[List["Ceiling", "[", "\[Infinity]", "]"]], "\[Equal]", "\[Infinity]"]]]]
<math xmlns='http://www.w3.org/1998/Math/MathML' mathematica:form='TraditionalForm' xmlns:mathematica='http://www.wolfram.com/XML/'> <semantics> <mrow> <mrow> <mo> ⌈ </mo> <mi> ∞ </mi> <mo> ⌉ </mo> </mrow> <mo> ⩵ </mo> <mi> ∞ </mi> </mrow> <annotation-xml encoding='MathML-Content'> <apply> <eq /> <apply> <ceiling /> <infinity /> </apply> <infinity /> </apply> </annotation-xml> </semantics> </math>
Cell[BoxData[RowBox[List[RowBox[List["HoldPattern", "[", RowBox[List["Ceiling", "[", "\[Infinity]", "]"]], "]"]], "\[RuleDelayed]", "\[Infinity]"]]]]
2001-10-29