<?php
// configuring monolog loggers
$monolog1 = new \Monolog\Logger('foo');
$monolog2 = new \Monolog\Logger('bar');

// registering them for lf4php
$loggerFactory = StaticLoggerBinder::$SINGLETON->getLoggerFactory();
$loggerFactory->setRootMonologLogger($monolog1);
$loggerFactory->registerMonologLogger($monolog2);

<?php
$logger = LoggerFactory::getLogger(__CLASS__);
$logger->info('Message');
$logger->debug('Hello {}!', array('John'));
$logger->error(new \Exception());