Question: If you're running focal fossa, are you using linux?, Answer:Yes, Description of Linux: Family of free and open-source software operating systems based on the Linux kernel, Fact1: Focal Fossa is the most recent Ubuntu release., Fact2: Ubuntu is a Linux distribution. 
Step1: Which operating system was codenamed focal fossa?, Step2: Is #1 a Linux distribution?, Wikipedia page for step 1: Ubuntu version history, Wikipedia page for step 2: Ubuntu, not_definitive_answer: False, incorrect_answer: False