symfony/src/Symfony/Bundle/FrameworkBundle/Resources/config/translation.xml

<?xml version="1.0" ?>

<container xmlns="http://www.symfony-project.org/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.symfony-project.org/schema/dic/services http://www.symfony-project.org/schema/dic/services/services-1.0.xsd">

    <parameters>
        <parameter key="translator.class">Symfony\Bundle\FrameworkBundle\Translation\Translator</parameter>
        <parameter key="translator.identity.class">Symfony\Component\Translation\IdentityTranslator</parameter>
        <parameter key="translator.selector.class">Symfony\Component\Translation\MessageSelector</parameter>
        <parameter key="translation.loader.php.class">Symfony\Component\Translation\Loader\PhpFileLoader</parameter>
        <parameter key="translation.loader.xliff.class">Symfony\Component\Translation\Loader\XliffFileLoader</parameter>
        <parameter key="translator.fallback_locale">en</parameter>
    </parameters>

    <services>
        <service id="translator.real" class="%translator.class%">
            <argument type="service" id="service_container" />
            <argument type="service" id="translator.selector" />
            <argument type="collection">
                <argument key="cache_dir">%kernel.cache_dir%/translations</argument>
                <argument key="debug">%kernel.debug%</argument>
            </argument>
            <argument type="service" id="session" on-invalid="ignore" />
            <call method="setFallbackLocale"><argument>%translator.fallback_locale%</argument></call>
        </service>

        <service id="translator" class="%translator.identity.class%">
            <argument type="service" id="translator.selector" />
        </service>

        <service id="translator.selector" class="%translator.selector.class%" />

        <service id="translation.loader.php" class="%translation.loader.php.class%">
            <tag name="translation.loader" alias="php" />
        </service>

        <service id="translation.loader.xliff" class="%translation.loader.xliff.class%">
            <tag name="translation.loader" alias="xliff" />
        </service>
    </services>
</container>