classes.dot

strict digraph {
  graph [layout=dot; overlap=false; rankdir=LR; nodesep=0.5];
  subgraph types {
    node [shape=oval];
    Integer -> Rational [label="(%1)"];
  }
  subgraph classes {
    node [shape=square];
    edge [arrowhead=diamond; style=dashed];
    Num;
    Real;
    Real -> Num;
    Integral -> Real;
    Fractional -> Num;
    Floating -> Fractional;
    RealFrac -> {Real; Fractional};
    RealFloat -> {RealFrac; Floating};
  }
  subgraph methods {
    edge [color=red];
    Integer -> Num [label=fromInteger];
    Real -> Rational [label=toRational];
    Integral -> Integer [label=toInteger];
    Rational -> Fractional [label=fromRational];
    RealFrac -> Integral [label=round];
  }
  subgraph cluster_legend {
    graph [label=legend];
    A -> B [label=function];
    X -> Y [color=red; label="typeclass method"];
    { node [shape=square];
      C1 -> C2 [arrowhead=diamond; style=dashed; label=inheritance];
    }
  }
}