You don't need to do anything to define the process group(s) used in PRC_MARK; they are implicit groupings.
Just choose some unique identifier (GAMS label) for the group, and use if for all the PRC_MARK that define the market share constraints for that group. You can of course use the same group label for UP/LO constraints.
In VEDA, you just need to put the label into the Other_Indexes column (works in ~FI_T, ~TFM_INS, ~TFM_UPD, ~TFM_DINS).
In ANSWER, PRC_MARK has been implemented as a special type of UC, and so there the label is the UC_N name. In both applications, filter masks for process names can be used for defining the PRC_MARK, which makes its use easy and compact.
Example:
PRC_MARK('UK','2020','PRC1','TESTGRP','CARPKM','UP') = 0.6;
PRC_MARK('UK','2020','PRC2','TESTGRP','CARPKM','UP') = 0.3;
With these two PRC_MARK parameters, the group is implicitly defined as: {PRC1, PRC2}. No need to define it any other way.
Just choose some unique identifier (GAMS label) for the group, and use if for all the PRC_MARK that define the market share constraints for that group. You can of course use the same group label for UP/LO constraints.
In VEDA, you just need to put the label into the Other_Indexes column (works in ~FI_T, ~TFM_INS, ~TFM_UPD, ~TFM_DINS).
In ANSWER, PRC_MARK has been implemented as a special type of UC, and so there the label is the UC_N name. In both applications, filter masks for process names can be used for defining the PRC_MARK, which makes its use easy and compact.
Example:
PRC_MARK('UK','2020','PRC1','TESTGRP','CARPKM','UP') = 0.6;
PRC_MARK('UK','2020','PRC2','TESTGRP','CARPKM','UP') = 0.3;
With these two PRC_MARK parameters, the group is implicitly defined as: {PRC1, PRC2}. No need to define it any other way.