How to determine that a list of objects belongs to the same sentence.

How can I determine that the same conditions apply to a list of mathematical objects? How would I note this, for example? $ C_1 $ and $ C_2 $ are members of the real numbers without defining the condition for each term separately? That means how would I simplify: $ C_1 in mathbb {R}, quad $ $ C_2 in mathbb {R} $?