Properties
An informal notion of translation is not sufficient to help determine expressivity of languages, as it permits trivial encodings such as mapping all elements of A to the same element of B. Therefore, it is necessary to determine the definition of a "good enough" encoding. This notion varies with the application. Commonly, an encoding is expected to preserve a number of properties.Preservation of compositions
; soundness : For every n-ary operator of A, there exists an n-ary operator of B such that : ; completeness : For every n-ary operator of A, there exists an n-ary operator of B such that :