Dear colleagues, I would like to ask for your assistance in order to declare specific parts in the definition field. I have three doubts:

1) How to implement a sum in definition in AIMMS in which one of the variables does not start from the first item?

Example:* **i**=1**4**j**=1**6**(**C**prod**.**P**i**,**j**+**C**est**.**E**i**,**j**)+**j**=2**6**(**C**aum**.∆**P**i**,**j**+**+**C**red**.∆**P**i**,**j**-**)*

2) How to implement an expression in definition in AIMMS that considers operations with two subsequent items (in different times)?

Example: *E**i**,**j**=**P**i**,**j**+**E**i**,**j**-1**-**PD**i**,**j*

3) How to implement a value assignment for a specific indexed item in definition in AIMMS?

Example: *P**1,6**=1500*

Thanks for you assistance.