protected void traceResult(boolean matches, RuleEvaluation e) {
        if (matches && e.getTraceLevel() >= 3)
            e.trace(3, "Matched '" + this + "'" + getMatchInfoString(e) + " at " + e.previousItem());
        if (!matches && e.getTraceLevel() >= 4)
            e.trace(4, "Did not match '" + this + "' at " + e.currentItem());
    }
Check start anchor. Trace level 4 if no match
container-search/src/main/java/com/yahoo/prelude/semantics/rule/Condition.java