<< I have one question for the list. Where can I find an exact
definition of the term 'class' by Marx/Engels and Lenin?
>>
In Marx's case, famously, you cannot. The treatment of class in Capital Vo;. 3 breaks off after a page. Marx's notion has to be constriucted contextually from its role in the theory. There is no reason to think that Engels' notion differs from Marx's. This notion, very roughly, has an objective side, involving an understanding of class position in terms of an individual's control or lacxk of it over (a) her own labor power and (b) means of production, and a more complex social and subjectyive side, involving awareness of the objective aspect and common bonds of solidaroty with others similarly situated. Lenin defines class variously in different places depending on his purposes.
--jks