Minor language edit
diff --git a/Doc/lib/libmailbox.tex b/Doc/lib/libmailbox.tex
index 50dd3dd..0a1f792 100644
--- a/Doc/lib/libmailbox.tex
+++ b/Doc/lib/libmailbox.tex
@@ -230,7 +230,7 @@
create=True}}}
A subclass of \class{Mailbox} for mailboxes in Maildir format. Parameter
\var{factory} is a callable object that accepts a file-like message
-representation (which behaves as if open in binary mode) and returns a custom
+representation (which behaves as if opened in binary mode) and returns a custom
representation. If \var{factory} is \code{None}, \class{MaildirMessage} is used
as the default message representation. If \var{create} is \code{True}, the
mailbox is created if it does not exist.
@@ -356,7 +356,7 @@
\begin{classdesc}{mbox}{path\optional{, factory=None\optional{, create=True}}}
A subclass of \class{Mailbox} for mailboxes in mbox format. Parameter
\var{factory} is a callable object that accepts a file-like message
-representation (which behaves as if open in binary mode) and returns a custom
+representation (which behaves as if opened in binary mode) and returns a custom
representation. If \var{factory} is \code{None}, \class{mboxMessage} is used as
the default message representation. If \var{create} is \code{True}, the mailbox
is created if it does not exist.
@@ -409,7 +409,7 @@
\begin{classdesc}{MH}{path\optional{, factory=None\optional{, create=True}}}
A subclass of \class{Mailbox} for mailboxes in MH format. Parameter
\var{factory} is a callable object that accepts a file-like message
-representation (which behaves as if open in binary mode) and returns a custom
+representation (which behaves as if opened in binary mode) and returns a custom
representation. If \var{factory} is \code{None}, \class{MHMessage} is used as
the default message representation. If \var{create} is \code{True}, the mailbox
is created if it does not exist.
@@ -516,7 +516,7 @@
\begin{classdesc}{Babyl}{path\optional{, factory=None\optional{, create=True}}}
A subclass of \class{Mailbox} for mailboxes in Babyl format. Parameter
\var{factory} is a callable object that accepts a file-like message
-representation (which behaves as if open in binary mode) and returns a custom
+representation (which behaves as if opened in binary mode) and returns a custom
representation. If \var{factory} is \code{None}, \class{BabylMessage} is used
as the default message representation. If \var{create} is \code{True}, the
mailbox is created if it does not exist.
@@ -579,7 +579,7 @@
\begin{classdesc}{MMDF}{path\optional{, factory=None\optional{, create=True}}}
A subclass of \class{Mailbox} for mailboxes in MMDF format. Parameter
\var{factory} is a callable object that accepts a file-like message
-representation (which behaves as if open in binary mode) and returns a custom
+representation (which behaves as if opened in binary mode) and returns a custom
representation. If \var{factory} is \code{None}, \class{MMDFMessage} is used as
the default message representation. If \var{create} is \code{True}, the mailbox
is created if it does not exist.