t = O (_t1::a)
()
t = O ((_t2::a1) : (_t3::[a1]))
()
t = O ((_t4::a2) : (_t5::a2) : (_t6::[a2]))
()
t = O ((_t7::Maybe [a1]) : Just [(_t8::a1),(_t9::a1)] :
       (_t10::[Maybe [a1]]))
()
t = O ((_t11::Maybe [Integer]) : Just [2,(_t12::Integer)] :
       (_t13::[Maybe [Integer]]))
()
t = O (Just [(_t14::Integer),(_t15::Integer)] :
       Just [2,(_t16::Integer)] : (_t17::[Maybe [Integer]]))