ELC - illegal "complementary" in gate file

 Hi all,

 I am trying to characterize a differential receiver using elc by using a gate model to specify the cell's behaviour. For the gate file, I copied the example given in the user guide, since its behaviour is the same as our custom cell:

DESIGN (DIN);
    //PORT SECTION;
    INPUT P (P);
    INPUT N(N);
    OUTPUT Y (Y);
    SUPPLY1 VDD (VDD);
    SUPPLY0 VSS (VSS);
    COMPLEMENTARY P, N;
    //GATE SECTION
    AMP (Y, P, N);
END_OF_DESIGN; 

However, I get the following warning right after the db_gsim command:

-----------------------------------
[WARNING(db_gsim)] illegal line in gate file :
 COMPLEMENTARY
 P
 N

[WARNING(db_gsim)] The gate file will not be used for circuit recognition.
------------------------------------

 If I remove the "complementary" statement, the simulation vector inputs are not differential, and are therefore not valid for characterization.

I tried using "db_diff DIN P N" before the call to db_gsim instead, with no changes in the results. We are using version v08.13-s001_1 - linux_x86 32-bit.

 Any ideas how to correct this situation?

 Thanks