lib/position/bk.js
function pass1(elem) {
    xs[elem] = blockG.inEdges(elem).reduce(function(acc, e) {
      return Math.max(acc, xs[e.v] + blockG.edge(e));
    }, 0);
  }
function pass1(elem) {
    xs[elem] = blockG.inEdges(elem).reduce(function(acc, e) {
      return Math.max(acc, xs[e.v] + blockG.edge(e));
    }, 0);
  }
function pass1 ( elem ) { xs [ elem ] = blockG . inEdges ( elem ) . reduce ( function ( acc , e ) { return Math . max ( acc , xs [ e . v ] + blockG . edge ( e ) ) ; } , 0 ) ; }
First pass, assign smallest coordinates
First pass assign smallest coordinates