code: function fromListPush(toPush, nodes)
  {
  	var h = toPush.height;
  
  	// Maybe the node on this height does not exist.
  	if (nodes.length === h)
  	{
  		var node = {
  			ctor: '_Array',
  			height: h + 1,
  			table: [],
  			lengths: []
  		};
  		nodes.push(node);
  	}
  
  	nodes[h].table.push(toPush);
  	var len = length(toPush);
  	if (nodes[h].lengths.length > 0)
  	{
  		len += nodes[h].lengths[nodes[h].lengths.length - 1];
  	}
  	nodes[h].lengths.push(len);
  
  	if (nodes[h].table.length === M)
  	{
  		fromListPush(nodes[h], nodes);
  		nodes[h] = {
  			ctor: '_Array',
  			height: h + 1,
  			table: [],
  			lengths: []
  		};
  	}
  }
docs: Push a node into a higher node as a child.