One other related question; when an equation contains single words between operation signs and all are uncontracted, why the use of switch indicators for single words? The equation is already stated as being Nemeth by the opening indicator. example;
13 years × $2,176 per year = $28,288.
This part of the code is most troublesome, it doesn't seem to be clearly defined. More types of examples would help, the guidelines are inadequate.