[Texmacs-dev] phantom, vphantom, hphantom

[Álvaro Tejero Cantero]

Hello,


Sometimes I must align multiline formulas in a way that is logical, i.e.
I want the second line to start not at the same point as the previous
but rather a little to the right.

My solution to this (please, tell me if you have a better idea) is to
insert a \phantom space of the size of the prefactor in the above line. 

An example will make it clear.:

a = 1/2*(b + c -     
    ----d + f) 

instead of filling "-----" with spaces, I do insert \phantom{1/2*}. The
result is very nice, but when the height of the prefactor 1/2 is not the
same as the maximum height inside the delimiters (when it is a newline
in the same cell) then the sizes of the automatic delimiters suffer,
because the closing delimiter takes as maximum height the height of the
prefactor, which is not intended.

Therefore, I would like to ask whether if it is possible to add two
primitives to TeXmacs: 

                \vpanthom and \hpanthom

in order to get a more precise control in this situation (and hopefully,
others).

I then would use \hphantom to insert the desired horizontal space but
not the vertical.

In the end, I would like to automate this by writing a macro for
generating phantom space up to the first opening delimiter of the
previous line/cell.

Regards,

Álvaro.