Modular Forms

In Remark 3.1 on page 98, we discussed unimodular transformations in the context of binary quadratic forms involving SL(2,Z). Also, in Exercise 2.5 on page 66, the content therein is that two Z-modules having the same basis are connected by a unimodular transformation, namely via those A ∈ GL(2,Z) with det(A) = ±1.