Complex sentence: In mathematics, a rigid collection of mathematical objects (for instance sets or functions) is one in which every "c" ∈ "C" is uniquely determined by less information about "c" than one would expect.
Split into simpler sentences: In mathematics, suppose "C" is a collection of mathematical objects (for instance sets or functions). Then we say that "C" is rigid if every "c"\\ in "C" is uniquely determined by less information about "c" than one would expect.