1549055384-Symplectic_Geometry_and_Topology__Eliashberg_

Then we define

LECTURE 5. THE SYMPLECTIC CASE, PART II

1

!+,o = 1 -t'

! +,1=l+t,

l+t

!+,2 = 1 + t2'

f - (1 + t)(l - t^2 )

+,3 - 1 + t2 '

1

f-,k = -f.

+,k

Note that r ( C, m) is not always ± l.

139

This completes the definition of Gr. Another derivation of this invariant has
been given by Ionel and Parker [7].