--- Libc/Libc-498/pthreads/pthread_mutex_unlock.3
+++ Libc/Libc-391/pthreads/pthread_mutex_unlock.3
@@ -36,9 +36,7 @@
 .Sh SYNOPSIS
 .Fd #include <pthread.h>
 .Ft int
-.Fo pthread_mutex_unlock
-.Fa "pthread_mutex_t *mutex"
-.Fc
+.Fn pthread_mutex_unlock "pthread_mutex_t *mutex"
 .Sh DESCRIPTION
 If the current thread holds the lock on
 .Fa mutex ,
@@ -49,10 +47,10 @@
 .Sh RETURN VALUES
 If successful,
 .Fn pthread_mutex_unlock
-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_unlock
+.Fn pthread_mutex_trylock
 will fail if:
 .Bl -tag -width Er
 .It Bq Er EINVAL