High-definition television:

In 1981, the MUSE system was demonstrated for the first time in the United States, using the same 5:3 aspect ratio as the Japanese system. Upon visiting a demonstration of MUSE in Washington, US President Ronald Reagan was impressed and officially declared it "a matter of national interest" to introduce HDTV to the US.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". Which system was demonstrated in Washington to President Ronald Reagan?
MUSE