[logback-user] opposite of ThresholdFilter or LevelRangeFilter available?

Hi, does logback offer some functionality that can be thought of the opposite of the ThresholdFilter, i.e. I want an appender to log only events with levels BELOW and equal to the level specified. With log4j, there is the org.apache.log4j.varia.LevelRangeFilter available that can do such things, does something similar exists in logback? thanks in advance, regards, christian!