The meaning of v-ta+であろう


What does v-た+であろう mean? For example:

> ほんの一、ニ分のやりとりで **あったであろう** が、いかに屈託のない若い人たちの闊達さがさわやかであった。

Does it mean something is likely to be that way? But what then if it appears
that this thing has already happened?




It should be clear from a direct translation of the whole sentence:

> ほんの一、ニ分のやりとりであったであろうが、いかに屈託のない若い人たちの闊達さがさわやかであった。  
>  The exchange was probably _no more than_ * one or two minutes but the
> generosity of _those_ ** carefree young people was so refreshing.

_Notes_  
*ほんの really means "just" but "no more than" feels more natural so I've taken a little literary license. 

** We don't really have a word like その to represent "those" and you have not
given any more context so I've added it to make the sentence more complete as
a stand alone statement.

であった is past/perfect copula similar to だった or でした equivalent to "was"

であろう is similar to だろう & でしょう and equivalent to "probably".

_Comment_ : The grammar is fairly straight forward but this sentence contains
some quite difficult words. Did you read and understand the rest of the
sentence before asking the question?

