λ > 0xF0 0x9F 0xA5 0x9B
ω > wrap abstraction and application with brackets:
　　　0xF0 0x9F 0xA5 0x9B -> (0xF0 0x9F 0xA5 0x9B)
α > (((((((0 xF0)0)x9F)0)xA5)0)x9B)
ε > 　　　unbound variable: xF0 rename as x'0
> 　　　　unbound variable: x9F rename as x'1
> 　　　　unbound variable: xA5 rename as x'2
> 　　　　unbound variable: x9B rename as x'3
(((((((0 [x'0] )0) [x'1] )0) [x'2] )0) [x'3] )
β > (((((((0 x'0)0)x'1)0)x'2)0)x'3)
λ >