code: def matrix(self):
      localctx = AutolevParser.MatrixContext(
          self, self._ctx, self.state
      )
      self.enterRule(localctx, 28, self.RULE_matrix)
      self._la = 0  # Token type
      try:
          self.enterOuterAlt(localctx, 1)
          self.state = 249
          self.match(AutolevParser.T__0)
          self.state = 250
          self.expr(0)
          self.state = 255
          self._errHandler.sync(self)
          _la = self._input.LA(1)
          while _la == 10 or _la == 19:
              self.state = 251
              _la = self._input.LA(1)
              if not (_la == 10 or _la == 19):
                  self._errHandler.recoverInline(self)
              else:
                  self._errHandler.reportMatch(self)
                  self.consume()
              self.state = 252
              self.expr(0)
              self.state = 257
              self._errHandler.sync(self)
              _la = self._input.LA(1)
  
          self.state = 258
          self.match(AutolevParser.T__1)
      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 16 for calling the AutolevParser obj's underlying member method code with example usage: obj.matrix() and returns: localctx