我正在斯卡拉的基礎結構庫中進行生產或個人學習。我專注於清楚地描述任何類型理論,貓理論,集合論中的結構。其中一種類型, abstract case class Fold[A, B]() {
type I
def trans: I => A => I
def start: I
def output: I => B
def cojoin: Fold[A
Considering a language L, let L′ be the set of all first halves of strings in L so that
L′ ={x| for some y,|x|=|y|and xy ∈ L}
Please prove that if L is regular, then L′ is also regular by construc