The present research investigated the effects of negation on young and older adults’ comprehension of sentences. Participants read sentences, named probe words, answered comprehension questions, and completed the operation-span test. Negation adversely affected comprehension in both age groups such that probe word naming times were marginally slower and comprehension accuracy was reduced for ne...

Head moves are a type of rearrangement for phylogenetic net-works. They have primarily been studied as part other types moves, such rSPR moves. Here, we study head on themselves. We show that the tiers (k > 0) network space connected by local Then, tail and closely related: sequences can be converted into vice versa, changing length at most constant factor. Because this gives second proof conne...