forced <z1>
lazy val in scrutinee: ok
forced <z1>
lazy val in case: ok
lazy val in case: forced <z1>
ok
lazy val in if condition: forced <z1>
ok
lazy val in pattern: forced LazyField
ok
lazy val with patterns:
x and y: xy(x, y)
x1 and y1: x1y1(x1, y1)