The phrase "has so far established" is correct and usable in written English.
It can be used to indicate that something has been established up to the present moment, often in a context of ongoing progress or development.
Example: "The research team has so far established a clear correlation between diet and health outcomes."
Alternatives: "has to date established" or "has thus far established".
"Chinese high-speed rail has so far established a mortality-risk level that equals or exceeds that of the world's safest airlines," Mr. Barnett wrote in an e-mail.
It was as though the designer had used everything he has so far established — the models gracefully walking the stage, a sense of modesty (with pants under coats and skirts).
Ethiopia has so far established several protected areas, which cover about 16.4% of the total area of the country (Tessema et al. 2010).
Mr. Lind, an entrepreneur who in 1997 founded Strategic Partners, an emerging markets corporate finance firm specializing in telecommunications and finance, has so far established InQbiz incubators in Bombay, India, and Cape Town, South Africa.
Testimony has so far established that the government could not link Manning's leaks to any deaths.
However, no study has so far established the best time point for the re-examination of bone marrow after primary treatment.
Mr. Freitas, the District Attorney, said that the investigation begun three weeks ago into possible voting irregularities involving temple members had so far established that no such allegations had been brought to the attention of his office during Mr. Stoen's tenure there.
Many studies have so far established that transport costs have serious implications for the accessibility of health care for the people in need [ 29– 31].
We have so far established that by means of a competitive logic as a motivation, students playing the game in schools are encouraged to work towards a state of health and a better self in terms of an ideal body.
