And also commutative, if I remember my math right, so you can traverse them in both directions. Punning on the word ring (which is a math concept too, as in gro

And also commutative, if I remember my math right, so you can traverse them in both directions. Punning on the word ring (which is a math concept too, as in groups, rings and fields, and stretching the metaphor too, or is it a mixed metaphor? Heh.