graph TD
    subgraph Region2[Memory region 2]
        Processor3[Processor 3]
        Processor4[Processor 4]

        Processor3 --> Region2Value[Regional value]
        Processor4 --> Region2Value
    end

    subgraph Region1[Memory region 1]
        Processor1[Processor 1]
        Processor2[Processor 2]

        Processor1 --> Region1Value[Regional value]
        Processor2 --> Region1Value
    end