一个单形（Monomorph）会在 一致性检查（3.5） 时变形（morph）为另外一个类型。有关这一类型的进一步细节将在 类型推断（3.6）中进行解释。
A monomorph is a type which may, through unification(3.5), morph into a different type later. Further details about this type are explained in the section on type inference(3.6)