(fwiw, I like the article, and I find it suitably humble) Just want to hang a thought here ... depending on the precise definition of First Normal Form, it is

(fwiw, I like the article, and I find it suitably humble) Just want to hang a thought here ... depending on the precise definition of First Normal Form, it is either impossible to avoid[0] or impossible to enforce[1] without further constraints. [0] if definition is "must be rectangular", i.e. all columns have the same number of rows and all rows have the same number of columns. [1] if the definition includes "do not allow duplicate rows"