The phrase "assertion confirmed" is correct and usable in written English.
It can be used in contexts where you want to indicate that a statement or claim has been validated or accepted as true.
Example: "After reviewing the evidence, we can confidently say that the assertion confirmed our initial hypothesis."
Alternatives: "claim validated" or "statement verified".
He said it had nothing to do with the government's ability to raise money, an assertion confirmed by two recent bond auctions.
Mr. Kheri, in a phone interview from jail in Kabul, said he had been an informant for the Drug Enforcement Administration and United States intelligence agencies, an assertion confirmed by American counternarcotics and intelligence officials.
Although Mr. Smitherman was mayor during the 1965 march, he always said he was a moderate segregationist who played no role in the beatings, an assertion confirmed by many of those who were there.
Fifteen years ago, The New York Times Magazine titled a cover article "Why Sports Don't Matter Anymore," an assertion confirmed by today's conspicuous silence: an immigration battle rages in sports-crazed Arizona, while Latino baseball players have hardly said a word.
GoLocalWorcester notes that WAM has welcomed same-sex couples since gay marriage was legalized in the state in 2004, an assertion confirmed to HuffPost by Elefterion.
Biographers Peter Brown and Steven Gaines attribute the new musical direction to "the Beatles' now habitual use of marijuana", an assertion confirmed by the band – Lennon referred to it as "the pot album", and Starr said: "Grass was really influential in a lot of our changes, especially with the writers.
This assertion confirms Nsibambi (1998) that, in health, provision of medical care and services has fallen far short of local needs through lack of finances.
We assert things like "either there were an odd or an even number of dinosaurs on this planet independently of what anyone believes" and all our actions and other assertions confirm that we really do believe this.
A few weeks ago, Mr. Muhammad said the government had released 145 Taliban prisoners as a goodwill gesture, an assertion not confirmed by the government.
Lest anyone think the Greens are beyond reproach, said Mr. Dendahl, now weary of the whole ordeal, it took their leaders almost a month to inform him they would not take the offer, an assertion Mr. Wilson confirmed.
This assertion is confirmed by the author's research.
