In http://lists.wfu.edu/pipermail/gretl-users/2018-August/013277.html Artur gave a piece of hansl script that he reckoned ought to work but which in fact failed, namely creation of a list of first lags by direct reference to a list of series contained in a bundle: <hansl> open denmark.gdt -q list L = LRM LRY bundle b = null b.L = L b.L1 = b.L(-1) # fails here </hansl> In my initial reply I gave a rationalization for why this wouldn't work, but I now think I was mistaken, or at least almost mistaken! Another formulation in the close neighborhood works OK, namely that using the lags() function: b.L1 = lags(1, b.L) so why shouldn't the shorthand employed by Artur work too? Well, there's one long-standing blockage: to use notation such as "(-1)" to indicate taking a lag, either the term to the left must be a named series, or -- if it's a list rather than a series -- you must flag your intention to create a list by using the "list" keyword. So, even ignoring bundles, (a) below works but (b) doesn't open denmark.gdt -q list L = LRM LRY list L1 = L(-1) # (a), OK L2 = L(-1) # (b), fails If you're with me so far, here's the next step. It then seems that the following should work in Artur's context: # ought to work, right? list b.L1 = b.L(-1) # with "list" out front but that also failed. And that, I'd say, was a bug (or at least a missing feature). So it's now fixed in git. A list inside a bundle should be usable in the same sort of way as a list "on the loose", provided it validates as a list in the context of the current dataset (that is, none of the series ID numbers it contains are out of bounds). Allin