Comment by jart

It's useful to be able to calculate the density of information. For example, redbean uses it to determine whether or not it's profitable to apply gzip. It has nothing to do with isa. That's kind of the point. For example, I could have written a routine that said, don't bother compressing files with the extension jpeg, jpg, png, gz, zip, etc. or I could have used information theory like I did. Another cool example is I've never seen any code that has higher information density than biology.