# File kwartz.rb, line 1058
        def deepcopy
            node = self.dup
            (node.left  = @left.is_a?(Node)  ? @left.deepcopy  : @left.dup)  if @left
            (node.right = @right.is_a?(Node) ? @right.deepcopy : @right.dup) if @right
            (node.condition = @condition.is_a?(Node) ? @condition.deepcopy : @condition.dup) if @condition
            return node
        end