Now I'm curious what the target was. Are there any notable classes of programs/problems where you'd do an LU decomposition of this specific matrix?

`i` still shows up in my grep, though, for anything like a function call of the word `import(`. Even if it takes a search to figure out what calls `i`, you know something is fishy because `import(` is used at all instead of the `import` keyword. Whereas there's no easy distinguishment of "top-level" static require and dynamic require, it's always a function call. (You can Regex match a negative lookahead for calls that don't include static strings, but that's a much harder regex than the `import(` call regex I provided.)

(ETA: Even/especially in minified code. Something like `var r = require` is rather common in Code Golfing/minifying CommonJS so grepping all uses of require both static and dynamic is also complicated by nicknames. But ESM doesn't minify static import ever and yeah dynamic import might be minified, but that still means it sticks out as a sore thumb if it exists at all even in minified shapes. Especially in minified shapes because that often means it is used multiple times for a minifier to decide that minifying it is worth the tax of declaring the minified nickname.)