Principal ideal
A (left/right/two-sided) ideal
- left principal ideal iff
for someπΌ = π π ;π β π - right principal ideal iff
for someπΌ = π π ;π β π - two-sided principal ideal iff
for someπΌ = π π π .π β π
A ring in which every ideal is (left/right/two-sided) principal is called a (left/right/two-sided) principal ideal ring.