Writer/Math handling of unicode symbols

Thanks Regina. That's how I thought it worked. What confused me is that after inserting something like ⇄ and highlighting it in Writer, the font combobox doesn't change from Verdana (my initial font, which does not include ⇄). Furthermore, if I highlight ⇄ and change the font, it changes slightly each time, suggesting that there actually is a different symbol in each font.

On a related note, is it correct that Dejavu Sans is included in LibreOffice on all platforms?

Thanks.

- Glen