Compress[expr] gives a compressed representation of expr as a string.

ConditionalExpression[expr, cond] is a symbolic construct that represents the expression expr when the condition cond is True.

Conditioned[expr, cond] or expr \[Conditioned] cond represents expr conditioned by the predicate cond.

patt /; test is a pattern which matches only if the evaluation of test yields True. lhs :> rhs /; test represents a rule which applies only if the evaluation of test yields ...

Cone[{{x_1, y_1, z_1}, {x_2, y_2, z_2}}, r] represents a cone with a base of radius r centered at (x_1, y_1, z_1) and a tip at (x_2, y_2, z_2). Cone[{{x_1, y_1, z_1}, {x_2, ...

ConfidenceLevel is an option for LinearModelFit and other fitting functions that specifies the confidence level to use in generating parameter and prediction intervals.

ConfigurationPath is a global option that specifies which directories are searched for systemwide configuration information.

Congruent[x, y, ...] displays as x \[Congruent] y \[Congruent] ....

Conjugate[z] or z\[Conjugate] gives the complex conjugate of the complex number z.

ConjugateTranspose[m] or m^\[ConjugateTranspose] gives the conjugate transpose of m.