--- Libc/Libc-583/pthreads/pthread_mutex_lock.3
+++ Libc/Libc-320/pthreads/pthread_mutex_lock.3
@@ -36,9 +36,7 @@
 .Sh SYNOPSIS
 .Fd #include <pthread.h>
 .Ft int
-.Fo pthread_mutex_lock
-.Fa "pthread_mutex_t *mutex"
-.Fc
+.Fn pthread_mutex_lock "pthread_mutex_t *mutex"
 .Sh DESCRIPTION
 The
 .Fn pthread_mutex_lock
@@ -49,19 +47,19 @@
 .Sh RETURN VALUES
 If successful,
 .Fn pthread_mutex_lock
-will return zero.
-Otherwise, an error number will be returned to indicate the error.
+will return zero, otherwise an error number will be returned to
+indicate the error.
 .Sh ERRORS
 .Fn pthread_mutex_lock
 will fail if:
 .Bl -tag -width Er
-.It Bq Er EDEADLK
-A deadlock would occur if the thread blocked waiting for
-.Fa mutex .
 .It Bq Er EINVAL
 The value specified by
 .Fa mutex
 is invalid.
+.It Bq Er EDEADLK
+A deadlock would occur if the thread blocked waiting for
+.Fa mutex .
 .El
 .Sh SEE ALSO
 .Xr pthread_mutex_destroy 3 ,