Software cannot execute without hardware. It literally needs the electrons to exist. Executing software is used to achieve practically useful results. It is not abstract in the legal sense of the word. You're thinking, like most people here do, of "abstraction", which is a key aspect of software engineering. But in patent terms "abstract" has a meaning more along the lines of "not a practical application".

Abstract means non-concrete. I wasn't using it in a special software-engineering sense. In patent terms, it also means non-concrete, it doesn't mean impractical.

How is it non-concrete if it requires physical hardware and achieves practical results?