Mohammad The its not quite an and without parentheses.
[list[sample]] +[list[population]] The give the results I expect because the + and - prefixes operate on the list fed to it so far. [list[sample]] [list[population]] Would give you the content of both lists after removing duplicates. This is I think more like the and you perceive. The plus says members of first list and tests each title and passes only titles that are also found in the second list. Using a negative would say list members of the first list but remove those in the second list ie do not pass on those found in the second list. This is in part due to the filter nature each run follows the previous one and acts on the result of the previous run if you use - + or ~ Filters typically reduce the set first presented to a subset according to its conditions. For this reason the order is esentiial because one is the source the second is an operation ibn the members in the source. On way to look at is the second list has a leading operator so it will perform an operation on the list so far. Regards Tony -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to tiddlywiki+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/e738d0f1-4fa8-4fed-a32a-24ad96653e0d%40googlegroups.com.
