Consider a countable subgroup 
with elements 
and an element 
not in 
, then 
for 
, 2, ... constitute the right coset of the subgroup 
with respect to 
.
Right Coset
See also
Coset, Left CosetExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Right Coset." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/RightCoset.html