graph "G" {
layout=fdp;
subgraph "cluster_2" {
"n6";
"n32" [fixedsize="false"];
}
subgraph "cluster_6" {
"n4";
"n30" [];
}
"n4" -- "n41";
"n4" -- "n13";
"n4" -- "n6":"_" [label="e=mc²", arrowtail="crow"];
}