F : P(N)N P(N) F (x) = {x(i) | i " N}
F
F P(N)

-1
A Ä…" N ({A})
F

-1
A Ä…" N ({A})
F
k " N - {0} rk, r Ä…" Z × Z
x, y " rk x y x - y k
x, y " r x y x · y > 0
Ák = rk *" r
x " Z [x]Á k
k
Z/Á
k
k = 4
k = 3
T Ä…" P(N)× N a, x
" a, x " T b, x " T a Ä…" b a = b
Åš : {T Ä…" P(N) × N | T } P(N)P(N)
Åš(T )(a) = {x " N | "b (b Ä…" a '" b, x " T )}
Åš P(N)P(N)
T
Åš(T ) = idP(N)
Åš(T )
Åš