Help on new (1.6) mathmacro

[Neal Becker]

I'm trying to find a description of how to use the new mathmacro stuff. 
Attempting to insert a mathmacro I get something that appears to have input
for a name, TeX code, and LyX code.  I don't know what should go into
these.  I'm guessing that the box labeled TeX is for a TeX expansion of the
macro, but don't know what the box labeled LyX is for.