} else if(tag.equals(MathExpressionEntityMethodRef.TAG)) {
express = new MathExpressionEntityMethodRef(element,
cf.getChildContext(MathExpressionEntityMethodRef.GROUP));
} else if(tag.equals(MathExpressionEntityObjectFieldRef.TAG)) {
express = new MathExpressionEntityObjectFieldRef(element,
cf.getChildContext(MathExpressionEntityObjectFieldRef.GROUP));
} else if(tag.equals(MathExpressionEntityRef.TAG)) {
express = new MathExpressionEntityRef(element,
cf.getChildContext(MathExpressionEntityRef.GROUP));