public static boolean isOperand(final String s) {
    String symbol = s.toLowerCase(Locale.ENGLISH);
    return (!operators.contains(symbol));
  }
Evaluates whether symbol is operand.

@param s symbol.
@return true if operand.
olv-core/src/main/java/pl/otros/logview/accept/query/org/apache/log4j/rule/InFixToPostFix.java