Definition:Ideal


 * Ring Theory:
 * Definition:Ideal of Ring
 * Definition:Left Ideal of Ring
 * Definition:Right Ideal of Ring


 * Order Theory:
 * Definition:Ideal (Order Theory)


 * Join Semilattice:
 * Definition:Ideal (Join Semilattice)


 * Lattice Theory:
 * Definition:Ideal (Lattice)


 * Physics:
 * Definition:Ideal (Physics)