\class{Popen3} and \class{Popen4} classes from the \refmodule{popen2}
module; these are only available on \UNIX.
-For a discussion of possible dead lock conditions related to the use
+For a discussion of possible deadlock conditions related to the use
of these functions, see ``\ulink{Flow Control
Issues}{popen2-flow-control.html}''
(section~\ref{popen2-flow-control}).
When reading output from a child process that writes a lot of data to
standard error while the parent is reading from the child's standard
-out, a dead lock can occur. A similar situation can occur with other
+out, a deadlock can occur. A similar situation can occur with other
combinations of reads and writes. The essential factors are that more
than \constant{_PC_PIPE_BUF} bytes are being written by one process in
a blocking fashion, while the other process is reading from the other