Why googling “2 * -2” does not show any results?

[aramalipoor]

When you search "2 * -2" without quotes, Google results hang for a few seconds and only calculator is shown. Is this a bug?

If you try any other number it works fine, like "2 * -5"

[mbrubeck]

Maybe because "-foo" means "search for documents that do not contain foo", so queries like "foo -foo" never match anything:

https://www.google.com/search?q=foo+-foo