ragraph>Р<Paragraph> à ‘sub-title’< Paragraph > | ‘endnote’<Sub-paragraph > | ‘signature’Р<Sub-paragraph> à ‘sub-title’<Paragraph>Р其中‘title’, ‘sub-title’, ‘endnote’’,‘signature’等为终结符号。Р试求出描述此文法所产生语言的正规式。Р?【答案】Р方程组:Р< Article > = ‘title’<Text> (1)Р<Text> = ‘sub-title’<Paragraph> (2)Р<Paragraph> = ‘sub-title’<Paragraph> + ‘endnote’<Sub-paragraph> +’signature’?(3)Р<Sub-paragraph> = ‘sub-title’<Paragraph> (4)Р(4)代入(3)得:Р< Paragraph >?= ‘sub-title’< Paragraph > + ‘endnote’‘sub-title’< Paragraph > + ‘signature’Р= (‘sub-title’+ ‘endnote’‘sub-title’) < Paragraph > +‘signature’Р= (‘sub-title’|‘endnote’‘sub-title’)*‘signature’(5)Р(5)代入(2)得:Р<Text> =‘sub-title’( ‘sub-title’| ‘endnote’‘sub-title’)*‘signature’(6)Р(6)代入(1)得:Р< Article > = ‘title’‘sub-title’(‘sub-title’| ‘endnote’‘sub-title’)*‘signature’
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