A law is a mathematical statement which always holds true. Whereas "laws" in physics are generally experimental observations backed up by theoretical underpinning, laws in mathematics are generally theorems which can formally be proven true under the stated conditions. However, the term is also sometimes used in the sense of an empirical observation, e.g., Benford's law.
Law
See also
Absorption Law, Benford's Law, Contradiction Law, de Morgan's Duality Law, de Morgan's Laws, Elliptic Curve Group Law, Exponent Laws, Girko's Circular Law, Law of Cosines, Law of the Excluded Middle, Law of Sines, Law of Tangents, Law of Truly Large Numbers, Morrie's Law, Parallelogram Law, Plateau's Laws, Quadratic Reciprocity Theorem, Strong Law of Large Numbers, Strong Law of Small Numbers, Sylvester's Inertia Law, Trichotomy Law, Vector Transformation Law, Weak Law of Large Numbers, Zipf's LawExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Law." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Law.html