chain rule

This term is a technical mathematical expression used exclusively within the field of calculus. It describes a specific procedure for differentiating composite functions, where one function is nested inside another. In a classroom or academic setting, it is treated as a foundational tool rather than a general rule of logic.

Because it refers to a specific mathematical theorem, it is typically used as a singular count noun in instructional contexts, though it remains a fixed compound term. It is rarely used outside of mathematics, physics, or engineering contexts.