  We extract genus $0$ consequences of the all genera quantum HRR formula
proved in Part IX. This includes re-proving and generalizing the adelic
characterization of genus $0$ quantum K-theory found in [Givental A., Tonita
V., in Symplectic, Poisson, and Noncommutative Geometry, <I>Math. Sci. Res.
Inst. Publ.</I>, Vol. 62, Cambridge University Press, New York, 2014, 43-91].
Extending some results of Part VIII, we derive the invariance of a certain
variety (the "big J-function"), constructed from the genus $0$ descendant
potential of permutation-equivariant quantum K-theory, under the action of
certain finite difference operators in Novikov's variables, apply this to
reconstructing the whole variety from one point on it, and give an explicit
description of it in the case of the point target space.
