The phrase "already shown to exist" is correct and usable in written English.
It can be used when referring to something that has been previously demonstrated or proven to be real or present.
Example: "The theory is based on principles that have already shown to exist in various scientific studies."
Alternatives: "previously demonstrated to exist" or "already proven to exist".
So Russell postulated that only properties of mathematical objects that have already been shown to exist, determine classes.
Internalization of the CD34 receptor has already been shown to exist by receptor-mediated endocytosis [34].
Because the three subunits have already been shown to exist in 1 1 1 ratio in the purified noncaveolar kidney enzyme, 14) the combined data of panels A and D of Figure 1 indicate that the kidney caveolar enzyme also contains the three subunits in the same ratio.
Already shortly after its discovery 6S RNA was shown to exist in the cell as a ribonucleoprotein complex [ 11].
The distortion of the dispersion of the light waves or the nonphysical frequency alias is shown to exist in the Courant condition relaxed methods already proposed.
Already, symbolic culture has been shown to have existed among the Neanderthals, with 50,000-year-old evidence indicating body painting and jewellery decoration made from bones, teeth, ivory and marine shells, at sites in France.
We have already shown that there exists a homeomorphism (Phi ^) which makes the following diagram commute: (10) The map (Phi^) is just a composition between the fixed point (f^) and the homeomorphism that conjugates (sigma_{p}) to ψ. Taking the inductive limit on both sides of the diagram and using Proposition 6.1 of [1] completes the proof.
Quantitative studies have already shown that major differences exist regarding the decision-making and performance of CS in The Netherlands, Belgium and the UK [ 26, 27].
Considerable evidence has already shown that related genes tend to exist as clusters in the genome.
