[Haskell-beginners] Setting Default Integer and Real Types

[Lorenzo Isella]

Dear All,
I am quite new to Haskell and planning to see where it will lead me in 
scientific computing (I will be looking into hmatrix soon).
Unless there are real memory problems, I would like to make sure that 
all real numbers are Double and all integer numbers are Integer types.
Now, I understand that Haskell in most of the cases is smart enough to 
infer the type of a variable (integer, real, etc...), but can I also set 
its default precision once for all?
I.e. if I say a=5.2 I want a to be used as a double precision real 
everywhere in the code.
Cheers

Lorenzo