i tried that code and not working

<ifmodule mod_rewrite.c=""> 
Options +FollowSymLinks -MultiViews

RewriteEngine On 
RewriteBase /</ifmodule>

#removing trailing slash
RewriteCond %{REQUEST_FILENAME} !-d     
RewriteRule ^(.*)/$ $1 [R=301,L]

#www to non
RewriteCond %{HTTP_HOST} ^www.(([a-z0-9_]+.)?domain.com)$ [NC]
RewriteRule .? http://%1%{REQUEST_URI} [R=301,L]

#html
RewriteCond %{REQUEST_FILENAME} !-f 
RewriteCond %{REQUEST_FILENAME} !-d 
RewriteRule ^([^.]+)$ $1.html [NC,L]

#index redirect 
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /index.html\ HTTP/ 
RewriteRule ^index.html$ http://ghadaalsaman.com/ [R=301,L]
RewriteCond %{THE_REQUEST} .html 
RewriteRule ^(.*).html$ /$1 [R=301,L]

#moz
RewriteRule ^(.*)$ http://ghadaalsaman.com.com/$1/ [L,R=301]

My website is non www ,it has wordpress in subdirectory and some static webpages in the root and other subdirectory

1. i want to remove .html extention from the webpages in the root and
the others static webpages in subdirectory.
2. add slash at the end.
3. 301 redirect from non slash to url with slash.

so it should be

http://ghadaalsaman.com/articles.html to http://ghadaalsaman.com/articles/

and

http://ghadaalsaman.com/en/poem-list.html to http://ghadaalsaman.com/en/poem-list/

the below code

1. working with non slash at the end

**2. **redirect 301 url with slash to non

here's my .htaccess

<ifmodule mod_rewrite.c="">Options +FollowSymLinks -MultiViews

RewriteEngine On
RewriteBase /</ifmodule>

#removing trailing slash
RewriteCond %{REQUEST_FILENAME} !-d     
RewriteRule ^(.*)/$ $1 [R=301,L]

#www to non
RewriteCond %{HTTP_HOST} ^www.(([a-z0-9_]+.)?domain.com)$ [NC]
RewriteRule .? http://%1%{REQUEST_URI} [R=301,L]

#html
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([^.]+)$ $1.html [NC,L]

#index redirect
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /index.html\ HTTP/
RewriteRule ^index.html$ http://ghadaalsaman.com/ [R=301,L]
RewriteCond %{THE_REQUEST} .html
RewriteRule ^(.*).html$ /$1 [R=301,L]

PS everything is ok with the wordpress , the problems with static pages only.

Thanks in advanced