code: def HH(n):
      
      if (n<=0):return Context('1')
      else:
          LL1=LL(n-1)
          HH1=HH(n-1)
          r1 = C1(3**(n-1),2**(n-1)) - LL1 - HH1
          r2 = HH1 - HH1 - HH1
          return r1 + r2
docs: constructs the HH context