SLIDE 83 ❘♦s❡♥❜❡r❣ ❈❧❛ss✐✜❝❛t✐♦♥ ♦❢ ▼✐♥✐♠❛❧ ❈❧♦♥❡s ❚❤❡♦r❡♠ ❊❛❝❤ ♠✐♥✐♠❛❧ ❝❧♦♥❡ ♦♥ k ❡❧❡♠❡♥ts ❝❛♥ ❜❡ ❣❡♥❡r❛t❡❞ ❜② f ✇❤❡r❡
✶ f ✐s ❛♥ ✉♥❛r② ♦♣❡r❛t✐♦♥✳ ✷ f ✐s ❛ ❜✐♥❛r② ✐❞❡♠♣♦t❡♥t ♦♣❡r❛t✐♦♥ f(a, a) = a ❢♦r ❡✈❡r② a ∈ E3. ✸ f ✐s ❛ ♠❛❥♦r✐t② ♦♣❡r❛t✐♦♥
∀a, b ∈ E3 : f(a, a, b) = f(a, b, a) = f(b, a, a) = a
✹ f ✐s ❛ ♠✐♥♦r✐t② ♦♣❡r❛t✐♦♥
∀a, b ∈ E3 : f(a, a, b) = f(a, b, a) = f(b, a, a) = b
✺ f ✐s ❛ s❡♠✐♣r♦❥❡❝t✐♦♥ t♦ t❤❡ i✲t❤ ✈❛r✐❛❜❧❡
f ∈ Pn
k ✱ 3 ≤ n ≤ k✱ ❢♦r ❡✈❡r② t✉♣❧❡ (a1, a2, . . . , an) s❛t✐s❢②✐♥❣
|{a1, a2, . . . , an}| < n ✇❡ ❤❛✈❡ f(a1, a2, . . . , an) = ai✳
❲❡ ✇✐❧❧ ❛ss✉♠❡ t❤❛t i = 1 ❢♦r ❛❧❧ ♦❝❝✉rr✐♥❣ s❡♠✐♣r♦❥❡❝t✐♦♥s✳
❉♠✐tr✐② ❩❤✉❦ ③❤✉❦✳❞♠✐tr✐②❅❣♠❛✐❧✳❝♦♠ ✭▼♦s❝♦✇ ❙t❛t❡ ❯♥✐✈❡rs✐t②✮ ❖♣❡♥ Pr♦❜❧❡♠s ✐♥ ❈❧♦♥❡ ❚❤❡♦r② ❖♣❡♥ Pr♦❜❧❡♠s ✐♥ ❯❆ ✷✺ ✴ ✹✾