: [N]owhere does Marx’s LTV explain the difference between labor and mere physical exertion.
Ever heard of use-value?
As in 'the utility of a thing makes it a use-value' (page 2 of Capital, emphasis added)?
Or: 'A commodity is, in the first place, an thing that by its properties satisfies human wants of some sort or another' (Ibid, p. 1, emphasis added)?
Your x's and y's are real pretty, though...
What an army of straw men.