context dependencies

[Ricky Zhang]

I have read through 'handling context dependencies' section Bison manual.
But I still haven't figured out the proper solution to my problem.

We have production rule:

expr : expr SINGLE_SPACE expr { /* some operation */ }
        | expr + expr
        ...
        ;

expr: NUMBER
       | ID
       ;

and also for all white space [SINGLE_SPACE | \t]* in the language should be
ignored. Are there any easy way to solve it?

Thanks,
Ricky