MoebiusMu[n] gives the Möbius function \[Mu](n).
a ** b ** c is a general associative, but non-commutative, form of multiplication.
Opener
(Built-in Mathematica Symbol) Opener[x] represents an opener with setting x, displayed as OpenerBox[True] when x is True and OpenerBox[False] when x is False. Opener[Dynamic[x]] takes the setting to be ...
PrimeQ
(Built-in Mathematica Symbol) PrimeQ[expr] yields True if expr is a prime number, and yields False otherwise.
expr /. rules applies a rule or list of rules in an attempt to transform each subpart of an expression expr.
Round
(Built-in Mathematica Symbol) Round[x] gives the integer closest to x. Round[x, a] rounds to the nearest multiple of a.
RussellRaoDissimilarity[u, v] gives the Russell\[Dash]Rao dissimilarity between Boolean vectors u and v.
SeedRandom[n] resets the pseudorandom generator, using n as a seed. SeedRandom[] resets the generator, using as a seed the time of day and certain attributes of the current ...
SetAttributes[s, attr] adds attr to the list of attributes of the symbol s.
SetOptions[s, name_1 -> value_1, name_2 -> value_2, ...] sets the specified default options for a symbol s. SetOptions[stream, ...] or SetOptions["name", ...] sets options ...