Hyperstructures are algebraic structures equipped with at least one multi-valued operation, called a hyperoperation. The largest classes of the hyperstructures are the ones called
Hv
A hyperoperation
(\star)
H
H x H
P*(H)
H
\star:H x H\toP*(H)
(x,y)\mapstox\stary\subseteqH.
For
A,B\subseteqH
A\starB=cupaa\starb
A\starx=A\star\{x\},
x\starB=\{x\}\starB.
(H,\star)
(\star)
x\star(y\starz)=(x\stary)\starz
x,y,z\inH.
Furthermore, a hypergroup is a semihypergroup
(H,\star)
a\starH=H\stara=H
a\inH.