Yes, and there's also bold (𝛑), bold italic (𝝅), sans-serif bold (𝝿), and sans-serif bold italic (𝞹), all distinct from the run-of-the-mill Greek Small Lett

Yes, and there's also bold (𝛑), bold italic (𝝅), sans-serif bold (𝝿), and sans-serif bold italic (𝞹), all distinct from the run-of-the-mill Greek Small Letter Pi (π) which is often rendered quite differently from the "standard mathematical pi" in addition to, of course, being semantically different. There's a lot of fun stuff in the Mathematical Alphanumeric Symbols block (https://unicode-table.com/en/blocks/mathematical-alphanumeric-symbols/ https://unicode-table.com/en/blocks/mathematical-alphanumeri...)