So were did NeXT get it? Before that I assume “x” was a metaphor for crossing out the page of text or paragraph marking it invalid. That is probably not as uni

So were did NeXT get it? Before that I assume “x” was a metaphor for crossing out the page of text or paragraph marking it invalid. That is probably not as universal. Windows 3 was using “x” in checkboxes as well, I wonder if switching to checkmarks is connected to putting “x” on the “close window” button.