"is proof for" is correct and usable in written English.
You can use it when you want to express that something is evidence or proof that supports a particular claim. For example, "The study's results were clear: fewer than 5% of surveyed households reported a food shortage - this is proof for the effectiveness of the government's relief program."
Now there is proof for her friends back home that Eloise really does exist at the Plaza Hotel — just as she does in the books.
For now, landing Carsales, Australia's largest online car site, which is listed on the ASX, and other strategic investors is proof for the founders that they are on the right track.
For now, landing Carsales, Australia's largest online car site, which is listed on the ASX, and other strategic investors is proof for the founders that they are on the right track.
As for geographical expansion, TicketForEvent will start to market itself in the rest of Europe in about a year, although it already has customers in the UK, Austria, The Netherlands, Germany and the U.S. "This is proof for us that we are ready to face the competition in Europe and attract a good market share," he says.
He explained to Rosenberg the probable consequences when word of this got out: "I believe my reputation as an absolutely unreliable character will certainly be considerably enhanced among the biochemists…At least, there will not be many physical chemists who believe that someone's changing his mind is proof for utter lack of character.
As for geographical expansion, TicketForEvent will start to market itself in the rest of Europe in about a year, although it already has customers in the UK, Austria, The Netherlands, Germany and the U.S. "This is proof for us that we are ready to face the competition in Europe and attract a good market share," he says.
Rankin's supposed tears are proof for others of a calculated self-interest.
This will be proof for many that Nick Clegg is indeed a latte-sipping, windsurfing, arugula [rocket]-munching Euro-snob.
The two rows of radishes came up identical, and this was proof for me that no God existed.
The stomach-dropping video was proof for which no one had known they were waiting: that below the waves the rigs also walked.
It was proof for me that art can originate in pop culture and then be appreciated and acknowledged by the art world.
