Lemma Huanum
Lemma Huanum, ex Hua Loo-keng appellatum, in mathematica est aestimatio summarum exponentialium. Quae dicit si res P sit polynomialis per integrales aestimatus? gradús k, ε {\displaystyle \varepsilon } sit numerus realis positivus, et f sit functio realis per f ( α ) = ∑ x = 1 N exp ⁡ ( 2 π i P ( x ) α ) {\displaystyle f(\alpha )=\sum _{x=1}^{N}\exp(2\pi iP(x)\alpha )} definita, tum ∫ 0 1 | f ( α ) | λ d α ≪ P , ε N μ ( λ ) {\displaystyle \int _{0}^{1}|f(\alpha )|^{\lambda }d\alpha \ll _{P,\varepsilon }N^{\mu (\lambda )}} , ubi ( λ , μ ( λ ) ) {\displaystyle (\lambda ,\mu (\lambda ))} in linea polygonali iacet cum verticibus ( 2 ν , 2 ν − ν + ε ) , ν = 1 , … , k . {\displaystyle (2^{\nu },2^{\nu }-\nu +\varepsilon ),\quad \nu =1,\ldots ,k.}