ILOG OPL Development Studio Language Reference Manual

execute{writeln(s2);s1.add(3);writeln(s1,s2);}the result is:{1 2}{1 2 3} {1 2}whereas if you write:{int} s1={1,2};{int} s2={ i | i in s1};execute{//writeln(s2);s1.add(3);writeln(s1,s2);}the result is:{1 2 3} {1 2 3}Use the profiler feature to inspect the instantiation sequence of your model. See Profiling theexecution of a model in IDE Tutorials.See ILOG Script for OPL for details on the scripting language and its extensions for OPL.Lazy instantiationIt is important to be aware from OPL 5.2 onwards that during the process, declared elementsare instantiated on demand when referenced for the first time. See Data preprocessing inMigration from OPL 3.x (CP projects) for migration aspects.I L O G O P L D E V E L O P M E N T S T U D I O L A N G U A G ER E F E R E N C E M A N U A L77