Tombstone (typography)


In mathematics, the tombstone, halmos, end-of-proof, or Q.E.D. symbol "∎" is a symbol used to denote the end of a proof, in place of the traditional abbreviation "Q.E.D." for the Latin phrase "quod erat demonstrandum", meaning "which was to be demonstrated". In magazines, it is one of the various symbols used to indicate the end of an article.
In Unicode, it is represented as character. Its graphic form varies, as it may be a hollow or filled rectangle or square.
In AMS-LaTeX, the symbol is automatically appended at the end of a proof environment \begin... \end. It can also be obtained from the commands \qedsymbol, \qedhere or \qed.
It is sometimes called a "Halmos finality symbol" or "halmos" after the mathematician Paul Halmos, who first used it in a mathematical context in 1950. He got the idea of using it from seeing it was being used to indicate the end of articles in magazines. In his memoir I Want to Be a Mathematician, he wrote the following: