1)N2->BaN2 2)N2-> 3) B->a b FIRST FOLLOW +-+ B lah Predicting Analysis Table b # >b n2 1->a b 由预测分析表中无多重入口判定文法是LL(1)的 第2种改写 S->Aa b A->AaB bB B->ab 0) S->Aa 1)S->b 2) A->bB N3 5)B->a b FIRST FOLLOW SA-B0) S->b N2 1) N2->B a N2 2) N2->ε 3) B->a b =================================================== | | FIRST | FOLLOW | +-------+--------------------+--------------------+ | S | {b} | {#} | +-------+--------------------+--------------------+ | B | {a} | {a} | +-------+--------------------+--------------------+ | N2 | {ε,a} | {#} | =================================================== Predicting Analysis Table ========================================== | | a | b | # | +-------+----------+----------+----------+ | S | |->b N2 | | +-------+----------+----------+----------+ | B |->a b | | | +-------+----------+----------+----------+ | N2 |->B a N2 | |->ε | ========================================== 由预测分析表中无多重入口判定文法是 LL(1)的。 第 2 种改写： S->Aa|b A->AaB|bB B->ab 0) S->A a 1) S->b 2) A->b B N3 3) N3->a B N3 4) N3->ε 5) B->a b =================================================== | | FIRST | FOLLOW | +-------+--------------------+--------------------+ | S | {b} | {#} | +-------+--------------------+--------------------+ | A | {b} | {a} | +-------+--------------------+--------------------+ | B | {a} | {a} |