code: def supeq(self):
      localctx = LaTeXParser.SupeqContext(self, self._ctx, self.state)
      self.enterRule(localctx, 80, self.RULE_supeq)
      try:
          self.enterOuterAlt(localctx, 1)
          self.state = 516
          self.match(LaTeXParser.UNDERSCORE)
          self.state = 517
          self.match(LaTeXParser.L_BRACE)
          self.state = 518
          self.equality()
          self.state = 519
          self.match(LaTeXParser.R_BRACE)
      except RecognitionException as re:
          localctx.exception = re
          self._errHandler.reportError(self, re)
          self._errHandler.recover(self, re)
      finally:
          self.exitRule()
      return localctx
  
imports: from antlr4 import *
  from io import StringIO
  import sys
label_desc: Use image node_id 42 for calling the LaTeXParser obj's underlying member method code with example usage: obj.supeq() and returns: localctx