When first endpoint = previous last endpoint
This VALUE statement is valid, but is not equivalent to the revised VALUE statement above:

VALUE SCORE   0-65  ='F'
             65-70  ='D'
             70-80  ='C'
             80-90  ='B'
            90-HIGH ='A';

The same thing could be accomplished with:

VALUE SCORE   0-65  ='F'
             65<-70  ='D'
             70<-80  ='C'
             80<-90  ='B'
            90<-HIGH ='A';

That is, when the first-endpoint of a range is equal to the last-endpoint of the previous range (and that last-endpoint is included in the corresponding range), then the first-endpoint is not included.
Style: It is good form to be explicit about which endpoints are to be included and excluded.