  In this paper we describe the complexity of building a lemmatizer for Arabic
which has a rich and complex derivational morphology, and we discuss the need
for a fast and accurate lammatization to enhance Arabic Information Retrieval
(IR) results. We also introduce a new data set that can be used to test
lemmatization accuracy, and an efficient lemmatization algorithm that
outperforms state-of-the-art Arabic lemmatization in terms of accuracy and
speed. We share the data set and the code for public.
