The usual examples of synthetic a priori statements are – it seems at least since Kant:
"Nothing can be simultaneously red and green all over"
7 + 5 = 12 (or any other basic arithmetic statements).
Are there more complex examples than those two? Or at least a more diverse list of examples?
I'm just baffled by the extreme sparsity of examples here, especially since "synthetic a priori" is a difficult concept to grasp (ok, for analytic a priori the "bachelor" example gets recycled since hundreds of years, too. But at least the concept of analytic a priori is easy to understand).
Are there philosophers who study examples of synthetic a priori more seriously?