Uniform Cauchy criterion: Let EE be a set and let (Y,ρ)(Y,\rho) be a . A sequence of functions fn:EYf_n:E\to Y converges on EE if and only if it is , meaning: for every ε>0\varepsilon>0 there exists NN such that for all m,nNm,n\ge N and all xEx\in E,

ρ(fn(x),fm(x))<ε.\rho\bigl(f_n(x),f_m(x)\bigr)<\varepsilon.

Equivalently, uniform convergence is exactly convergence in the (and, for bounded real-valued functions, in the ).