similarity of external form, appearance or size.
A many-to-one mapping in effect representing (
see representation ) a pattern in the
domain of the mapping by a simpler pattern in its range. The product of applying a homomorphism is called a homomorph. Homomorphisms are important in establishing whether one
system is a
model of another and which properties of the original system the model retains. For each system one can
construct a
lattice of homomorphic simplifications. The inverse of a homomorphism is not a mapping. (
Krippendorff )
