Covariance and contravariance

• Covariance and contravariance of vectors, in mathematics and theoretical physics
• Covariance and contravariance of functors, in category theory
• Covariance and contravariance (computer science), whether a type system preserves the ordering ≤ of types

See also

• Covariance, in probability theory and statistics, the measure of how much two random variables vary together
• Covariance (disambiguation)