The transformation from one representation form to another at the same relative abstraction level, while preserving the subject system' s external behaviour (functionality and semantics).

In addition suitable contents:
[ abstraction ] [ al ] [ am ] [ an ] [ at ] [ av ] [ b ] [ be ] [ bj ] [ bs ] [ ec ] [ eh ] [ er ] [ es ] [ fo ] [ for ] [ fr ] [ function ] [ functional ] [ functionality ] [ h ] [ il ] [ in ] [ io ] [ it ] [ la ] [ li ] [ ma ] [ man ] [ na ] [ nc ] [ ne ] [ ng ] [ no ] [ ns ] [ om ] [ pr ] [ re ] [ ro ] [ sa ] [ sam ] [ se ] [ semantics ] [ st ] [ su ] [ subject ] [ sy ] [ system ] [ T ] [ th ] [ to ] [ tr ] [ transformation ] [ ve ] [ vi ] [ while ]