Their Lagrangians are union of spheres. They want a trivial $\R$ bundle on the space, so that the direct sum of $\R$ with the tangent bundle is trivial. (well, sometimes, a bundle is stably trivial, you just need to give it more rooms).
We choose trivialization $t$ and $t'$ for the two 'augmented' Lagrangian (are they jet bundle?).
A capping Lagrangian path in the oriented Lagrangians Grassmannian. (so, do I choose orientation of my Lagrangians? I guess I did, since I have trivializations, and I can substract that trivial line bundle.)
A stable capping trivialization is a trivialization of the capping path $L_{p,t} \oplus \R$, that interpolate the original trivializations on the two strands.
OK, these are the data. How do I provides orientation for the moduli spaces then?
We map the upper half-plane to the target space. actually, it is a constant map (what?) to $p$, and we consider the trivial vector bundle $\pi_p^*(T_p M)$. We define the Cauchy-Riemann tuple. $\xi, \eta, D$
well, a determinant line is a kernel minus cokernel, taking determinants.
If $L$ satisfies certain topological condition, then the moduli space of disks ending on $L$ is orientable.
But, how do we define the A-infinity structures? Why we count some disks with a negative sign? When we say we orient the 0-dim moduli space of the disks, that means plus-minus signs.