Consider the mutually recursive functions: even(n)=n=0\text{even}(n) = n = 0even(n)=n=0 or odd(n−1)\text{odd}(n-1)odd(n−1), and odd(n)=n≠0\text{odd}(n) = n \neq 0odd(n)=n=0 and even(n−1)\text{even}(n-1)even(n−1). What is even(5)\text{even}(5)even(5)?
true
false
undefined
0