This is a read/write property. However, you don't usually set the property itself (if you do, you would assign it a CARenderingStyle object instance, but rather you normally set the properties of the CARenderingStyle object it points to.
CAEngine ade = new CAEngine; ade.DefaultRenderingStyle.GeneralExpression = false;
When to use
Set this when you want to ensure an application-wide default behavior for all results values.