## Abstract.

We establish a congruence modulo four in the real Schubert calculus on the
Grassmannian of *m*-planes in $2m$-space.
This congruence holds for fibers of the Wronski map and a generalization to what we call
symmetric Schubert problems.
This strengthens the usual congruence modulo two for numbers of real solutions to
geometric problems.
It also gives examples of geometric problems given by fibers of a map whose
topological
degree is zero but where each fiber contains real points.

## Comments (0)