code: function locateNearestErrorRecoveryRule(state) {
              var stack_probe = stack.length - 1;
              var depth = 0;
  
              // try to recover from error
              for(;;) {
                  // check for error recovery rule in this state
                  if ((TERROR.toString()) in table[state]) {
                      return depth;
                  }
                  if (state === 0 || stack_probe < 2) {
                      return false; // No suitable error recovery rule available.
                  }
                  stack_probe -= 2; // popStack(1): [symbol, action]
                  state = stack[stack_probe];
                  ++depth;
              }
          }
docs: Return the rule stack depth where the nearest error rule can be found. Return FALSE when no error recovery rule was found. we have no rules now