In this paper we propose a framework for the definition and combination of specialized entailment engines, each of which able to deal with a certain aspect of language variability. Such engines are based on transformations, and we define them taking advantage of the conceptual and formal tools available from an extended model of Natural Logic (NL). Given a T,H pair, each engine performs atomic edits to solve the specific linguistic phenomenon it is built to deal with, and assigns an entailment relation as the output of this operation. NL mechanisms of semantic relations composition are then applied to join the output of each single engine, in order to obtain a global entailment judgment for a pair.