In abstract algebra, an isomorphism (Greek: ἴσος isos "equal", and μορφή morphe "shape")'s a bijective map f such that both f and its inverse f −1 are homomorphisms, for example, structure-preserving mappings. In the more general setting of category theory, an isomorphism's a morphism f:X→Y in a category for which there exists an "inverse" f −1:Y→X, with the property that both f −1f=idX and ff −1=idY. Informally,… (More on Isomorphism)