The process of abstraction is necessarily mental, twit. Unless you'd care to show me what a material act of abstraction looks like? Perhaps you mean that this mental process has material results? There really isn't much point is asserting that I am ignorant, you know I am not. What do you think labor-power is? It isn't limited to acts of labor carried out in the process of production is it? Or do you think that it is? Let's dispose of that illusion first if so.