As Steam Summer Sale kicked off, an important update to Pure Logic was released. The undo function is now [b]unlimited[/b], instead of the last-step-only undo that has been available so far. In addition, [b]any[/b] set signal can be [b]changed[/b] directly to the other colour/state, or [b]reset[/b] back to the original unset state. Judging by feedback in reviews and the discussion forums, I think these changes will be appreciated by quite a few. And hopefully it opens up for a wider range of solving strategies. Enjoy the update, and enjoy the Steam Summer Sale! :)