It is true that ambiguous types cause time-wasting frustration for many a beginner. The link that Imants gave helps clarify matters: https://www.haskell.org/tutorial/numbers.html Even better is the link to the Haskell report given at the end: https://www.haskell.org/onlinereport/decls.html#default-decls On Thursday, June 16, 2016, Imants Cekusins wrote:

default(Int)

allows to use integers anywhere in this module without specifying their ambiguous type each time, like this: (3::Int)

https://www.haskell.org/tutorial/numbers.html section 10.4

some other default types may be specified too somehow I was not aware of this

-- -- Kim-Ee