The ideal generated by a subset T of a ring R is the smallest ideal containing T.
Equivalently, (T)=I⊇T⋂I where I varies over all of the ideals in
R that contain T.
Equivalently, if $T = {t_i}{i=1}^n,then(T) = \left{\sum\limits{i=1}^n r_it_i\right},thesetofallformalsumsofelementsofTwithcoefficientsinR$.