Modulus
(Built-in Mathematica Symbol) Modulus -> n is an option that can be given in certain algebraic functions to specify that integers should be treated modulo n.
MoebiusMu[n] gives the Möbius function \[Mu](n).
NDSolve
(Built-in Mathematica Symbol) NDSolve[eqns, y, {x, x_min, x_max}] finds a numerical solution to the ordinary differential equations eqns for the function y with the independent variable x in the range ...
NHoldRest is an attribute which specifies that all but the first argument to a function should not be affected by N.
NoncentralChiSquareDistribution[\[Nu], \[Lambda]] represents a noncentral \[Chi]^2 distribution with \[Nu] degrees of freedom and noncentrality parameter \[Lambda].
NormalizedSquaredEuclideanDistance[u, v] gives the normalized squared Euclidean distance between vectors u and v.
NormFunction is an option for functions such as FindFit and NDSolve which gives a function to be minimized in generating results.
Numerator[expr] gives the numerator of expr.
ObservableModelQ[ss] gives True if the StateSpaceModel object ss is observable, and False otherwise.
On
(Built-in Mathematica Symbol) On[symbol::tag] switches on a message, so that it can be printed. On["name"] switches on a named group of messages.On[s] switches on tracing for the symbol s. On[m_1, m_2, ...