When sorting an (incremental and persistent) SAP, you generally move extremas left until you run into a smaller/equal extrema, gathering collisions along the way. However, that results in the collisions of end-points being exclusive (equal extrema don't collide). At first, I was thinking of moving left until a smaller (but not equal) extrema is found, but I'm pretty sure that would give incorrect collision results.
If I want equal values to properly collide (and uncollide), how would that handled?
