MathDB
Who is Mr Boole?

Source: 2017 China South East Mathematical Olympiad Day1 P2

July 30, 2017
functionmodular arithmeticalgebranumber theory

Problem Statement

Let xi{0,1}(i=1,2,,n)x_i \in \{0,1\}(i=1,2,\cdots ,n),if the value of function f=f(x1,x2,,xn)f=f(x_1,x_2, \cdots ,x_n) can only be 00 or 11,then we call ff a nn-var Boole function,and we denote Dn(f)={(x1,x2,,xn)f(x1,x2,,xn)=0}.D_n(f)=\{(x_1,x_2, \cdots ,x_n)|f(x_1,x_2, \cdots ,x_n)=0\}. (1)(1) Find the number of nn-var Boole function; (2)(2) Let gg be a nn-var Boole function such that g(x1,x2,,xn)1+x1+x1x2+x1x2x3++x1x2xn(mod2)g(x_1,x_2, \cdots ,x_n) \equiv 1+x_1+x_1x_2+x_1x_2x_3 +\cdots +x_1x_2 \cdots x_n \pmod 2, Find the number of elements of the set Dn(g)D_n(g),and find the maximum of nN+n \in \mathbb{N}_+ such that (x1,x2,,xn)Dn(g)(x1+x2++xn)2017.\sum_{(x_1,x_2, \cdots ,x_n) \in D_n(g)}(x_1+x_2+ \cdots +x_n) \le 2017.