Rewind

Flows that don't arbitrarily stop and rewind won't be Rewind Singlets. So depending on how strict is the definition, there won't be true Rewind Singlet machines.

There are cases where the Rewind machine is a version of the same machine, with the same name - in a situation where the Left-Right Doublet coincides with the Rewind Doublet. The classic Ninja Star is a well-known example of this (see Ninja Star and Nunchuck).

There are also cases where the Rewind Doublet coincides with the Reverse Doublet. The 1 Base foot slides Hip Slide and Chicken Out are the simplest examples of this.