Wrong logical expression

Hi,

The following code is wrong and I want to know if it's possible to correct it without using another variable:

IF var1 < ( sy-datum + 15 ).

var2 = 1.

ELSEIF var1 > ( sy-datum + 15 ) AND var1 < ( sy-datum + 30 ).

var2 = 2.

ENDIF.

The ABAP syntax checking doesn't allow the logical expression with the "+"... Is not possible or simply I don't know how to do that?

I know that I can do something like that:

var3 = sy-datum + 15.

But I don't want that solution if it's possible