code: def restore(self, removals):
          "Undo a supposition and all inferences from it."
          for B, b in removals:
              self.curr_domains[B].append(bf restore(self, removals):
          "Undo a supposition and all inferences from it."
          for B, b in removals:
              self.curr_domains[B].append(b)
docs: Undo a supposition and all inferences from it.