Head(Tail(Head(Head(L))))
Head(Head(Head(Tail(Head(Tail(L))))))
类似本题的另外叙述的几个题解答如下
()head(head(tail(tail(L))))设L=(a(c)b)(((e))))
()head(head(head(head(tail(tail(L))))))
()head(tail(head(tail(A))))
()H(H(T(H(T(H(T(L)))))))
()tail(L)=(((cd))(ef))
head(tail(L))=((cd))
head(head(tail(L)))=(cd)
tail(head(head(tail(L))))=(d)
head(tail(head(head(tail(L)))))=d
()head(tail(head(head(tail(tail(A))))))
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