All functions in Elm are curried by default. If you have "a function of 2 arguments", it's really a function that takes one argument and returns a function that takes another argument.

function.elm

fullName fName lName = fName ++ " " ++ lName
//<function> : String -> String -> String

fullName "Jesse"
//<function> : String -> String

lastName = fullName "Jesse"
//<function> : String -> String

lastName "Tomchak"
"Jesse Tomchak" : String

superName fname lname = (String.append fname " ") ++ lname
//<function> : String -> String -> String
superName "Jesse" "Tomchak"
"Jesse Tomchak" : String