Lemma
 Noun
A preliminary or auxiliary proposition demonstrated or accepted for immediate use in the demonstration of some other proposition, as in mathematics or logic.
More related articles

Lemma
Lemma may refer to:

Rising sun lemma
In mathematical analysis, the rising sun lemma is a lemma due to Frigyes Riesz, used in the proof of the Hardy–Littlewood maximal theorem. The lemma was a precursor in one dimension of the Calderón–Zygmund lemma.

Poincaré lemma

Riemann–Lebesgue lemma
In mathematics, the Riemann–Lebesgue lemma, named after Bernhard Riemann and Henri Lebesgue, is of importance in harmonic analysis and asymptotic analysis.

Gibbs lemma
In game theory and in particular the study of Blotto games and operational research, the Gibbs lemma is a result that is useful in maximization problems. It is named for Josiah Willard Gibbs.

Sisay Lemma
Sisay Lemma Kasaye (born 12 December 1990) is an Ethiopian longdistance runner.

Bhaskara's lemma
Bhaskara's is an identity used as a lemma during the chakravala method. It states that:

Rokhlin lemma
In mathematics, the Rokhlin lemma, or Kakutani–Rokhlin lemma is an important result in ergodic theory. It states that an aperiodic measure preserving dynamical system can be decomposed to an arbitrary high tower of measurable sets and a remainder of arbitrarily small measure. It was proven by Vladimir Abramovich Rokhlin and independently by Shizuo Kakutani. The lemma is used extensively in ergodic theory, for example in Ornstein theory and has many generalizations.

Osgood's lemma
In mathematics, Osgood's lemma, introduced by William Fogg Osgood (1899 ), is a proposition in complex analysis. It states that a continuous function of several complex variables that is holomorphic in each variable separately is holomorphic. The assumption that the function is continuous can be dropped, but that form of the lemma is much harder to prove and is known as Hartogs' theorem.

Switching lemma
In computational complexity theory, Håstad's switching lemma is a key tool for proving lower bounds on the size of constantdepth Boolean circuits. Using the switching lemma, Johan Håstad (1987 ) showed that Boolean circuits of depth k in which only AND, OR, and NOT logic gates are allowed require size