Subspace-based model merging: We utilise TIES to prune the task vectors τ 1 and τ 2 , retaining the top 20% parameters, resulting in refined vectors τ1 and τ2 (see Fig. ). We then fuse the vectors via Task Arithmetic to obtain the merged model as Θ (merge) = 1 2 2 i=1 τi . During the merging process, conflicts arising from differing signs in the parameters p are resolved by aligning the pruned vectors as follows: