Suggestion for inclusion of an example in the Math Guide for a minus sign superscript

When creating an equation for Writer using the Math tool, it was required to add a "-" (minus sign) as a free standing exponent. Not as a negative value, just a lone minus sign.  An example can be created using the following limit equation as an example:

lim from{x %tendto 6 sup -{} } { frac 2 (x-6)sup 3 }

Note the "6 sup -{}". The empty {} is required or the equation editor will expect a value, like -x or -5 or some unary operator. The {} appeases the robot and allows the free standing "-" to appear.  (The meaning is the limit as x approaches 6 from the negative side.)

An hour long search and trial and error session by two people was required before we stumbled on this solution.

Including an example of this usage would save the next person at least that much trying to figure this out.  I looked for this in the Unary/binary operation commands" section of the Math Guide (

BTW, If there is a location that would have lead us to this more easily it would be helpful if someone can point it out. Always willing to learn from others experience and knowledge.

Thank you.