History as revealed by Google Ngrams, I: UNIX

UNIX was apparently really first discovered in the 18th century, about fifty years before the American War of Independence. However, it wasn't until the 20th century that it gained wide-spread use, when it was repopularised by AT&T.

Source: Google Ngram Viewer.

Tip: Showing blocked syntactic movement in LaTeX with tikz(-qtree)

Minimal example showing how to indicate blocked/illegal syntactic movement in LaTeX using the tikz and tikz-qtree packages.

\documentclass{article}
\usepackage{tikz}
\usepackage{tikz-qtree}
\begin{document}
\begin{tikzpicture}[baseline,description/.style={fill=white,inner sep=2pt}]
  \Tree [.A [.B \node(b){b}; ] [.C c [.D d [.E e [.F f [.G g [.H \node(h){h}; ]]]]]]]
  \draw [dashed, ->, bend left] (h) to node [description] {\LARGE $\times$} (b);
\end{tikzpicture}
\end{document}

Thanks to Andy Lücking and Alexis Dimitriadis from the Ling-TeX mailing list.