f1 (x,y) = x
f2 (x # y) = x
f3 [x,y,z] = x + y + z
f4 {x = a, y = b } = a
f5 ((x : [8]) # (y : [10])) = x # y : [10]
f6 (x # y : [10]) = x
f7 (x # (y : [10])) = x

/*
if a then b else c : [10]

let {} in a : [10]

case a : [10] of { }

// f (a :# b :: Int) = 


(fa,fb) = f6

*/