code: def p_minus_assignment(self, t):
      '''minus_assignment : IDENT EQ MINUS'''
      self.accu.add(Term('obs_vlabel', [self.name,"gen(\""+t[1]+"\")","-1"])f p_minus_assignment(self, t):
      '''minus_assignment : IDENT EQ MINUS'''
      self.accu.add(Term('obs_vlabel', [self.name,"gen(\""+t[1]+"\")","-1"]))
docs: minus_assignment : IDENT EQ MINUS