Space may be kept #1
Description
"a b" should keep the space. I.e., the MathML should display as 𝑎 𝑏. This is the choice made in the Microsoft implementation. The current spec is ambiguous. In the doersino implementation, a space is used to form single letters which will then be converted to math italic. In the Microsoft implementation, all ASCII letters and lowercase Greek letters are converted to math italic unless the letters comprise the name of a function or are inside quotes. Both approaches are valid interpretations of the current spec. But since the Microsoft implementation is widely used, we should implement its approach. That approach removes a space that's used to build up an expression or converts a LaTex control word. It also deletes a space that precedes or follows a binary/relational operator, since the display engine adds appropriate math spacing around such operators. Otherwise, it includes spaces.