(pointing out the obvious) This of course using BETWEEN makes the assumption that the expression can be expressed as a contiguous range of values (i.e. you don't need to exclude values within the range). It's OK as long as the question can indeed be expressed as "if X is between A and Z then ..", rather than being more of "if X is A, B, C or D then ..." (w/ potential for adding conditions T, X, and Y).

Anyway... examples of BETWEEN:

IF BETWEEN(n,1,3) THEN
    ...
ENDIF

would be the same as:

IF n >= 1 AND n<=3 THEN
    ...
ENDIF

And in SQL

SELECT ... FROM ... WHERE N BETWEEN 1 AND 3

would be equivalent to:

SELECT ... FROM ... WHERE N>=1 AND N<=3

>BETWEEN
>
>>What is the function to replace a statement like
>>
>>if n = 1 or n = 2 or n = 3
>>
>>by something shorter. I thought it would be something like if n in(1,2,3)