A set {uα}α∈Λ\left\{ u_{\alpha} \right\}_{\alpha \in \Lambda}{uα}α∈Λ of continuous functions uα:X→[0,1],α∈Λu_{\alpha} : X \to [0,1], \alpha \in \Lambdauα:X→[0,1],α∈Λ that satisfies the conditions below is called a Partition of Unity.∑α∈Λuα(x)=1 \sum _{\alpha \in \Lambda}u_{\alpha}(x)=1 α∈Λ∑uα(x)=1
