Abstract:

We study rough approximations in ternary groupoids via congruences and stable congruences. Upper and lower rough ternary subgroupoids and n-left ideals are introduced. We prove that every ternary subgroupoid forms an upper rough ternary subgroupoid (for any congruence) and a lower rough ternary subgroupoid (for any stable congruence). Likewise, each n-left ideal induces upper and lower rough $n$-left ideals.