A model transformation is a process of automatic
generation of a target model from a source model,
according to a transformation definition, which is
expressed in a model transformation language.
A model transformation is defined in a model transformation
specification, which consists of a set of transformation
rules. A transformation rule usually includes two parts:
a Left-Hand Side (LHS) and a Right-Hand Side (RHS). The LHS
defines the configuration of objects in the source models
to which the rule applies (i.e., filtering, which produces
a subset of elements from the source model). The RHS define
s the configuration of objects in the target models that
will be created, updated or deleted by the rule. Both the
LHS and RHS can be represented using any mixture of
variables, patterns and logic.