private PPCGEnv env = null;
public CGOperation(PPCGEnv myenv) {
env = myenv;
aUnifyCG = new UnifyCG(env);
// Created for each instance/call of CGOperation
// Cree pour chaque instance/appel a CGOperation
concMatchVec = new Vector<ConceptMatch>();
relMatchVec = new Vector<RelationMatch>();
}