EN
A graph property is any nonempty isomorphism-closed class of simple (finite or infinite) graphs. A graph property 𝓟 is of finite character if a graph G has a property 𝓟 if and only if every finite induced subgraph of G has a property 𝓟. Let 𝓟₁,𝓟₂,...,𝓟ₙ be graph properties of finite character, a graph G is said to be (uniquely) (𝓟₁, 𝓟₂, ...,𝓟ₙ)-partitionable if there is an (exactly one) partition {V₁, V₂, ..., Vₙ} of V(G) such that $G[V_i] ∈ 𝓟_i$ for i = 1,2,...,n. Let us denote by ℜ = 𝓟₁ ∘ 𝓟₂ ∘ ... ∘ 𝓟ₙ the class of all (𝓟₁,𝓟₂,...,𝓟ₙ)-partitionable graphs. A property ℜ = 𝓟₁ ∘ 𝓟₂ ∘ ... ∘ 𝓟ₙ, n ≥ 2 is said to be reducible. We prove that any reducible additive graph property ℜ of finite character has a uniquely (𝓟₁, 𝓟₂, ...,𝓟ₙ)-partitionable countable generating graph. We also prove that for a reducible additive hereditary graph property ℜ of finite character there exists a weakly universal countable graph if and only if each property $𝓟_i$ has a weakly universal graph.