Need help with LookML REPLACE

[Chingle]

hi, I’m attempting to create a custom field to replace all state names (such as ‘New York’) with their respective 2-letter abbreviations (such as ‘NY’). 

I’m brand new to LookML, and when writing my expression, it successfully works when I only include 1 replace function, but how will I link 50 (one for each state) together? When I type my 2nd entry, I get an “Expression incomplete” error