Rig
A rig is a generalized ring which may lack negatives.
That is, a rig
- left-distributivity
π β ( π + π ) = ( π β π ) + π β π ) - right-distributivity
( π + π ) β π = ( π β π ) + ( π β π ) - left-annihilation
0 β π = 0 - right-annihilation
π β 0 = 0
where