How old is Adaline?

Computer Science Level 2

What would the following haskell code print?

current_year = 2015   
andy_birth = 1984   
andy_minus_adaline = 4   
adaline = andy - andy_minus_adaline   
andy = current_year - andy_birth   

main = putStrLn $ show adaline

Bonus: How does a similar piece of code behave in each of Python? What about Mathematica?

Inspiration: Calvin's Problem