22 D. MCDUFF, INTRODUCTION TO SYMPLECTIC TOPOLOGY
Therefore, we may set
L(3 + s) = A(L(2 - s)), 0::; s::; 1.
The Maslov index μ u(x-,x+) is now defined to be the element in n 1 (.C(n)) ~ Z
represented by this path.
Exercise 3.14. Check that this index is independent of choices.