Bad RangeValue encoding when defined as "minus than n" and then "n to n+x"

[chapuisk]

Issue:
When reading string based range data value into explicit integer range value, it happens that the first category is define as "minus than n" with the next category being from n to n+x. In this case, the exact value n is contained in two different category, i.e. [0,n] and [n,n+x]

Expectation:
When reading range data value, make sure there is no overlapping between categories