I don't even know if this would be a correct name for this, or if it's even close, but i couldn't think of anything else.
Basically, this exercise is the ring curl which slizzardman shows here:
But what you do is get into a full FL (or full lay) position, and THEN do the ring curl. It's not a full FL pullup. The arms are in a supinated/chin-up grip for this.
Is this even possible? Has any gymnast/anyone ever done this before?