《离散数学》试题和答案.doc

文档介绍：一、填空题1设集合A,={1,2,3},B={1,2},则A-B=____________________; r(A)-r(B)=,|A|=n,则|r(A×A)|=={a,b},B={1,2},则从A到B的所有映射是_______________________________________,=Ø(P®Q)∧、B为两个集合,A={1,2,4},B={3,4},则从AÇB=_________________________;AÈB=_________________________;A-B=,________________________,=Ø(P®(QÙR)).,={1,2,3,4},A上的关系R1={(1,4),(2,3),(3,2)},R1={(2,1),(3,2),(4,3)},则 R1·R2=________________________,R2·R1=____________________________, R12=,B.|A|=m,|B|=n,则||r(A´B)|=,B,={x|-1≤x≤1,xÎR},B={x|0≤x<2,xÎR},则A-B=__________________________,B-A=__________________________,A∩B=__________________________,.={2,3,4,5,6}.(列举法)="xP(x)®$xQ(x).。{a,b},将表达式"xR(x)