Nest
(Built-in Mathematica Symbol) Nest[f, expr, n] gives an expression with f applied n times to expr.
BooleanConvert[expr] converts the Boolean expression expr to disjunctive normal form.BooleanConvert[expr, form] converts the Boolean expression expr to the specified ...
HeavisideTheta[x] represents the Heaviside theta function \[Theta](x), equal to 0 for x < 0 and 1 for x > 0. HeavisideTheta[x_1, x_2, ...] represents the multidimensional ...
CompiledFunction[args...] represents compiled code for evaluating a compiled function.
CounterFunction is an option for counters that specifies the symbols used to display the value of the counter.
NearestFunction[data] represents a function whose values give the elements closest to an element that is supplied.
BesselK
(Built-in Mathematica Symbol) BesselK[n, z] gives the modified Bessel function of the second kind K_n (z).
TransformationFunction[data] represents a transformation function that applies geometric and other transformations.
MultilineFunction is an option for UnderscriptBox and related box objects that specifies what to do when the contents of a box object are too long to fit on one line.