[texhax] Multicols is not enough

[Johan Glimming]

(paraphrase of the _World_ is not enough):

I am using multicols environment to show maths in two columns, e.g. 
inference rules but sometimes the division of the page width is "too 
good", e.g.

__________________________________________________
|                                                | page width
   short                  bloody long premise
   -----                 ------------------------
   short                  bloody long conclusion
|>                      |                       <|

is not as nice as

__________________________________________________
|                                                | page width
         short       bloody long premise
         -----     ------------------------
         short      bloody long conclusion
       |>       |                          <|

I.e. I want multicols to split up into columns that
are not of equal width, and also center the result as
required.

Is this possible?

Johan Glimming.