text: import seuif97 as if97
  
  
  class Node(object):
  
      def __init__(self):
          self.p = None
          self.t = None
          self.h = None
          self.s = None
          self.v = None
          self.x = None
  
      def pt(self):
          self.h = if97.pt2h(self.p, self.t)
          self.s = if97.pt2s(self.p, self.t)
          self.v = if97.pt2v(self.p, self.t)
          self.x = None
  
      def ph(self):
          self.t = if97.ph2t(self.p, self.h)
          self.s = if97.ph2s(self.p, self.h)
          self.v = if97.ph2v(self.p, self.h)
          self.x = if97.ph2x(self.p, self.h)
  
      def ps(self):
          self.t = if97.ps2t(self.p, self.s)
          self.h = if97.ps2h(self.p, self.s)
          self.v = if97.ps2v(self.p, self.s)
          self.x = if97.ps2x(self.p, self.s)
  
      def hs(self):
          self.t = if97.hs2t(self.h, self.s)
          self.p = if97.hs2p(self.h, self.s)
          self.v = if97.hs2v(self.h, self.s)
          self.x = if97.hs2x(self.h, self.s)
  
      def px(self):
          self.t = if97.px2t(self.p, self.x)
          self.h = if97.px2h(self.p, self.x)
          self.s = if97.px2s(self.p, self.x)
          self.v = if97.px2v(self.p, self.x)
  
      def tx(self):
          self.p = if97.tx2p(self.t, self.x)
          self.h = if97.tx2h(self.t, self.x)
          self.s = if97.tx2s(self.t, self.x)
          self.v = if97.tx2v(self.t, self.x)
  