v1 = {x:1.0,y:0.0}
v2 = {x:1.0,y:0.0,z:10.0}
v3 = {v1:v1, v2:v2}
f v = v.x +! v.y
g v = v.v1.x +! v.v2.z

x h = (h v3).x
z h = (h v3).x.c.v -- [x, c, v]

main = case f v1 +! f v2 +! g v3 of
    13.0 -> True
    _ -> False

{-
projection:
 - term .indents
 - term.indents

composition:
 - term . term
 - term. term
-}