IEEE 754 Representation

Is it okay to use lower bits for a type tag?

>>15

You can also "run" the program with pencil and paper

But then you would be running it. Whereas if you typecheck it on paper, you won't be running it. Feel the difference? In one case you run it (doesn't matter the hardware: laptop, workstation, cluster, brain), in the other you don't run it. That's why typechecking is a logically phase logically separated from runtime. Even if it might happen at the same time.