the books in our library中的in our library 在这里是什么 是定语从句？

.先行词为all, few, little, much, the one, something, anything, everything, nothing等时。如： （1）We'll do all that we can to protect the endangered plants and animals. 我们将尽我们的更大勤奋来庇护那些濒危的动动物。