I am not so sure the example provided helps me understand its real use. To me his example resembles something the compiler would handle by filtering out code that is never used. I suppose that the example could be more complete with a conditional use of F3 later on, implying if the condition is not met then C={F3 30} would be skipped.<p>Appreciate the article, confused me at least which means I will probably look into such ideas more even if in my field I will never use them