I have a weird error using "sin" and "cos" functions. For instance, when running the code of the TRIGX,SEQ=388 example (https://www.gams.com/latest/gamslib_ml/ ... trigx.html), the result is

***** MODEL STATUS 5 Locally Infeasible*

and the expansion of the constraints:

*con1.. x - sin(2*x + 3*y) - cos(3*x - 5*y) =e= 0;*

con2.. y - sin(x - 2*y) + cos(x + 3*y) =e= 0;

con2.. y - sin(x - 2*y) + cos(x + 3*y) =e= 0;

are

*con1.. - (1)*x - (3)*y =E= 0 ; (LHS = -1, INFES = 1 ****)*

con2.. - (1)*x + (3)*y =E= 0 ; (LHS = 1, INFES = 1 ****)

con2.. - (1)*x + (3)*y =E= 0 ; (LHS = 1, INFES = 1 ****)

quite strange... it seems as if GAMS were evaluating cos and sin at some fixed argument instead of taking the nonlinear functions defined in the expressions.

The the same happens with my own GAMS code using "cos" and "sin" (an OPF model). I'm using a GAMS Community license with the following distribution:

*GAMS Distribution 35.2.0*

GAMS Release: 35.2.0 r33388c4 WEX-WEI x86 64bit/MS Windows

Release Date: Jun 2, 2021

GAMS Release: 35.2.0 r33388c4 WEX-WEI x86 64bit/MS Windows

Release Date: Jun 2, 2021

Any idea...? Thank you!!

Javier