code: def p_edgesigs(self, p):
          'edgesigs : edgesigs SENS_OR edgesig'
          p[0] = p[1] + (p[3],)
          p.set_lineno(0, p.lineno(1)f p_edgesigs(self, p):
          'edgesigs : edgesigs SENS_OR edgesig'
          p[0] = p[1] + (p[3],)
          p.set_lineno(0, p.lineno(1))
docs: edgesigs : edgesigs SENS_OR edgesig