内容发布更新时间 : 2025/7/27 0:17:55星期一 下面是文章的全部内容请认真阅读。
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GO(I0,A)={ S?A?S,S??AS,S??b,A??SA,A??a}=I4 GO(I3,a)={ A?a?}=I1 GO(I3,b)={ S?b?}=I2
GO(I3,S)={ A?S?A,S??AS,S??b,A??SA,A??a}=I5
GO(I3,A)={ A?SA?,S?A?S,S??AS,S??b,A??SA,A??a}=I6 GO(I4,a)={ A?a?}=I1 GO(I4,b)={ S?b?}=I2
GO(I4,S)={ S?AS?,A?S?A,S??AS,S??b,A??SA,A??a}=I7 GO(I4,A)={ S?A?S,S??AS,S??b,A??SA,A??a}=I4 GO(I5,a)={ A?a?}=I1 GO(I5,b)={ S?b?}=I2
GO(I5,S)={ A?S?A,S??AS,S??b,A??SA,A??a}=I5
GO(I5,A)={ A?SA?,S?A?S,S??AS,S??b,A??SA,A??a}=I6 GO(I6,a)={ A?a?}=I1 GO(I6,b)={ S?b?}=I2
GO(I6,S)={ S?AS?,A?S?A,S??AS,S??b,A??SA,A??a}=I7 GO(I6,A)={ S?A?S,S??AS,S??b,A??SA,A??a}=I4 GO(I7,a)={ A?a?}=I1 GO(I7,b)={ S?b?}=I2
GO(I7,S)={ A?S?A,S??AS,S??b,A??SA,A??a}=I5
GO(I7,A)={ A?SA?,S?A?S,S??AS,S??b,A??SA,A??a}=I6 项目集规范族为C={I1,I2,I3,I4,I5,I6,I7}
(3)不是SLR文法
状态3,6,7有移进归约冲突
状态3:FOLLOW(S’)={#}不包含a,b
状态6:FOLLOW(S)={#,a,b}包含a,b,;移进归约冲突无法消解 状态7:FOLLOW(A)={a,b}包含a,b;移进归约冲突消解 所以不是SLR文法。
(4) 构造例如LR(1)项目集规范族 见下图: 对于状态5,因为包含项目[A?AS? a/b],所以遇到搜索符号a或b时,应该用A?AS归约。又因为状态5包含项目[A??a a/b],所以遇到搜索符号a时,应该移进。因此存在“移进-归约”矛盾,所以这个文法不是LR(1)文法。
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b b b 1: 5: 8: S??S? #A?SA? a/bS?A?S a/b A A?S?A a/bS?A?S a/bS??AS a/b A A A??SA a/bS??AS a/bS??b a/b A??a a/bS??b a/bA??SA a/b S??AS a/bA??SA a/bA??a a/b S S??b a/bA??a a/b a