//            A               A
//          /  \            /   \
//        B     C         B       C
//       / \    |        / \     / \
//      D   E   F       D   E   F   F
//     / \ / \ / \     / \ / \ / \ / \
//     1 2 3 4 5 6     1 2 3 4 5 6 5 6

digraph MerkleTrees {
    // General settings
    rankdir=TB;
    //node [shape=none, style=filled, color=lightblue];
    node [shape=box, width=0, height=0];
    ranksep=0.3;
    nodesep=0.1

subgraph cluster_x {
    // Merkle Tree 1
    A1 [label="A"];
    B1 [label="B"];
    C1 [label="C"];
    D1 [label="D"];
    E1 [label="E"];
    F1 [label="F"];
    x1 [label="1"]; 
    x2 [label="2"]; 
    x3 [label="3"]; 
    x4 [label="4"]; 
    x5 [label="5"]; 
    x6 [label="6"]; 
    
    A1 -> B1;
    A1 -> C1;
    B1 -> D1;
    B1 -> E1;
    C1 -> F1;
    D1 -> {x1, x2};
    E1 -> {x3, x4};
    F1 -> {x5, x6};
}


subgraph cluster_y {
    // Merkle Tree 2
    A2 [label="A"];
    B2 [label="B"];
    C2 [label="C"];
    D2 [label="D"];
    E2 [label="E"];
    F2 [label="F"];
    F2_dup [label = "F" ];
    y1 [label="1"]; 
    y2 [label="2"]; 
    y3 [label="3"]; 
    y4 [label="4"]; 
    y5 [label="5"]; 
    y6 [label="6"]; 
    y5_dup [label="5"]; 
    y6_dup [label="6"]; 
    
    A2 -> B2;
    A2 -> C2;
    B2 -> D2;
    B2 -> E2;
    C2 -> {F2, F2_dup};
    D2 -> {y1, y2};
    E2 -> {y3, y4};
    F2 -> {y5, y6};
    F2_dup -> {y5_dup, y6_dup};
}
}