code: def UV_H(self):
          
          h = reduce(lambda x,y:x&y,(H(g,self.width-1) for g in self))
          return UV_H(h, self.width)
docs: UV = all non-trivial (!V⊂U) implications U->V with UuV closed; in ternary coding (1=V,2=U)
          K = all closed sets
  
          This is UV_H function, but the returned implications are respected by all attribute sets of this context.
          This corresponds to a multiplication or & operation of the Hg sets.