MatchLocalNames is an option for Trace and related functions that specifies whether symbols such as x should match symbols with local names of the form x$nnn.
MatchQ
(Built-in Mathematica Symbol) MatchQ[expr, form] returns True if the pattern form matches expr, and returns False otherwise.
MathieuCharacteristicA[r, q] gives the characteristic value a_r for even Mathieu functions with characteristic exponent r and parameter q.
MathieuCharacteristicB[r, q] gives the characteristic value b_r for odd Mathieu functions with characteristic exponent r and parameter q.
MathieuCharacteristicExponent[a, q] gives the characteristic exponent r for Mathieu functions with characteristic value a and parameter q.
MathieuC[a, q, z] gives the even Mathieu function with characteristic value a and parameter q.
MathieuCPrime[a, q, z] gives the derivative with respect to z of the even Mathieu function with characteristic value a and parameter q.
MathieuGroupM11[] represents the sporadic simple Mathieu group M_11.
MathieuGroupM12[] represents the sporadic simple Mathieu group M_12.
MathieuGroupM22[] represents the sporadic simple Mathieu group M_22.