Entering <, <= and <> as values

I use soapUI to test web methods that process HQL/OQL queries. One field I enter a value in is the operator. I can enter =, <, <= and != but if I try <, <= or <>, the color turns from black to blue and nothing happens when I submit the request. I take the blue to mean those symbols are treated as XML instead of literal characters but I haven't found a literal character option like "\" in Java. Therefore, I believe this is a bug. Any help would me much appreciated.