+@c PSPP - a program for statistical analysis.
+@c Copyright (C) 2017 Free Software Foundation, Inc.
+@c Permission is granted to copy, distribute and/or modify this document
+@c under the terms of the GNU Free Documentation License, Version 1.3
+@c or any later version published by the Free Software Foundation;
+@c with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
+@c A copy of the license is included in the section entitled "GNU
+@c Free Documentation License".
+@c
@node Combining Data Files
@chapter Combining Data Files
@cmd{ADD FILES}, @cmd{MATCH FILES}, and @cmd{UPDATE} commands. The
following sections describe details specific to each command.
-Each of these commands reads two or more input files and combines them.
+Each of these commands reads two or more input files and combines them.
The command's output becomes the new active dataset.
None of the commands actually change the input files.
Therefore, if you want the changes to become permanent, you must explicitly
system-missing value for numeric variables or spaces for string
variables.
+These commands may combine any number of files, limited only by the
+machine's memory.
+
@node ADD FILES
@section ADD FILES
@vindex ADD FILES
@end display
@cmd{UPDATE} updates a @dfn{master file} by applying modifications
-from one or more @dfn{transaction files}.
+from one or more @dfn{transaction files}.
@cmd{UPDATE} shares the bulk of its syntax with other @pspp{} commands for
combining multiple data files. @xref{Combining Files Common Syntax},