The phrase "a demonstration to which" is correct and usable in written English.
It can be used when referring to a specific demonstration that is being discussed or described in relation to something else.
Example: "The conference featured a demonstration to which all attendees were invited to participate."
Alternatives: "a demonstration that" or "a demonstration for which".
The VASA cases were used as a demonstration to locate the problem, which was largely in the hospital.
The six women responded by organising a demonstration at which they urged each other to take action.
This included information sheets and a link to a demonstration video which were sent directly to practice managers and senior GP partners asking for the dissemination all GPs within the surgery.
Then 'Abd al-Latif passes to present al-Farabi's Aristotle who holds that the perfection of man sought by Plato is not self-evident or easy to explain by way of a demonstration which leads to certainty.
Secondly, to invest on fully commercial terms to create a demonstration effect which others will follow".
A federal judge ruled yesterday that city officials violated the First Amendment nearly four years ago when they blocked a demonstration in which taxi drivers planned to flood the Queensboro Bridge and Broadway with their cars during the morning rush hour.
The current push for a state funeral for Thatcher is in part a demonstration of the extent to which her image became almost that of a royal by proxy.
A demonstration setup, which allows studying the possible technical implementations of this electrochemical process, is described.
The scene outside City Hall was instead a demonstration of the extent to which Mr. Bloomberg, as the new mayor's aides like to point out, won office with fewer obligations than any mayor in memory.
During the intermission, Coleman invited an extreme-body-modification performance artist named Fakir Musafar to offer a demonstration — which featured young people in various states of undress being pierced through the cheeks, breasts, and other seemingly un-pierceable body parts.
