Must technological change be pure labor savings in an endogenous model of production growth?

Existing production models have not deeply analyzed the reasons why technical progress should be pure labor-saving in the models that consider endogenous technological innovations. Thus, in order to fill this gap in the literature, we do a mathematical deduction of the generalization of Uzawa's theorem in an endogenous model and discuss its implications in the economic growth theory. It was found that, contrasting the classical result of Uzawa's theorem, in order for technological innovations in the long term to be purely labor-saving, the production model must have the following characteristics: 1) the elasticity of substitution between labor and capital must be less than one and 2) the expansion of the technological frontier must only due to the increase of innovations that save work in the long term. Otherwise, technological change will not only be work-saving, but also capital-saving.