From: Aiya-Oba on
Sum of the set of pair of even numbers less than 10, and the set of
pair of odd numbers less than 10, equals prime 89. -Aiya-Oba
(Philosopher).

Thus, { a } + { b } = 89

Where a, is {8,6,4,2,0,2,4,6,8}, and b, is {9,7,5,3,1,3,5,7,9}.

Such that,

(8+6+4+2+0+2+4+6+8) + (9+7+5+3+1+3+5+7+9) = 89

= ( 40 ) + ( 49 ) = 89

= 89 = 89

QED