I believe that is what is being shown. The tool is (I think) being demonstrated in a zshell with that feature (and probabaly countless others) turned on, so it

I believe that is what is being shown. The tool is (I think) being demonstrated in a zshell with that feature (and probabaly countless others) turned on, so it is difficult to tell what is shell and what is percol. Or maybe not. The point is I don't know.