Prove or disprove:
For all functions $f:\Bbb Z^+ \to \{0,1\}$ , the following is true: There exists positive integers n and d such that: $$f(n)=f(n+d)=f(n+2d)=f(n+3d)$$
Prove or disprove:
For all functions $f:\Bbb Z^+ \to \{0,1\}$ , the following is true: There exists positive integers n and d such that: $$f(n)=f(n+d)=f(n+2d)=f(n+3d)$$