code: def binom(self):
      localctx = LaTeXParser.BinomContext(self, self._ctx, self.state)
      self.enterRule(localctx, 56, self.RULE_binom)
      self._la = 0  # Token type
      try:
          self.enterOuterAlt(localctx, 1)
          self.state = 353
          _la = self._input.LA(1)
          if not (
              (((_la - 69)) & ~0x3F) == 0
              and ((1 << (_la - 69)) & 7) != 0
          ):
              self._errHandler.recoverInline(self)
          else:
              self._errHandler.reportMatch(self)
              self.consume()
          self.state = 354
          self.match(LaTeXParser.L_BRACE)
          self.state = 355
          localctx.n = self.expr()
          self.state = 356
          self.match(LaTeXParser.R_BRACE)
          self.state = 357
          self.match(LaTeXParser.L_BRACE)
          self.state = 358
          localctx.k = self.expr()
          self.state = 359
          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 30 for calling the LaTeXParser obj's underlying member method code with example usage: obj.binom() and returns: localctx