but using the code used for the left term.
(The image is created using
\left(1 + \left(f(x),g(x)\right)\right) and
\Big(1 + \big(f(x),g(x)\big)\Big))
I could simply use
\Big, ... but I don't want to keep track of the content all the time.
I have no clue how to define a new set of
\right for this purpose.