Selection set logic

[Shane Gray]

I've noticed an issue in the past, but not spent time checking, with
selection sets, in particular the selector sentence.

Consider the following selection set:

 Group   Field  Heading                 Rel    Value  
------------------------------------------------------
                                                      
 a      .  1  . Branch                  ge .   QL.    
 b      .  1  . Branch                  le .   SS.    
 c      .  1  . Branch                     .   AA.    
        .     .                            .          
                                                      
------------------------------------------------------
Selector Sentence:                                    
a and b or c                                          

I believe the selector sentence should evaluate the same as "(a and b) or c"
giving a result with all the branch codes from QL to SS as well as AA.  

It would however seem to evaluate the same as "a and (b or c)" giving a
result with only branch codes between QL and SS.  No AA.

I have confirmed this by actually putting the parentheses in for both
options.  Is it that the selector sentence doesn't follow order of
precedence?

I have tested this up to 5.0.14 on SCO rclerk/rreport.  

Can anyone confirm this is an issue (or alternately that I am an imbecile).
I could of course be just using it incorrectly.

Thanks
Shane.