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f(x,y)=3(x+y)+32xy f(x,y)=3(x+y)-32xy f(x,y)=3(x+y)-16xy f(x,y)=3(x+y)+16xy
f(x,y)=3(x+y)-32xy f(x,y)=3(x+y)-16xy f(x,y)=3(x+y)+32xy f(x,y)=3(x+y)+16xy
f(x,y)=3(x+y)+32xy f(x,y)=3(x+y)-32xy f(x,y)=3(x+y)-16xy f(x,y)=3(x+y)+16xy
若X→Y,X→Z,则X→YZ 若XY→Z,则X→Z,Y→Z 若X→Y,Y→Z则X→Z 若X→Y,Y'
Y,则X→Y'
若X→Y,且存在Y的真子集Y,X→Y',则称Y对X部分函数依赖 若X→Y,且存在Y的真子集Y',XY',则称Y对X部分函数依赖 若X→Y,且存在X的真子集X',X'→Y,则称Y对X部分函数依赖 若X→Y,且存在X的真子集X',X'Y,则称Y对X部分函数依赖
f(x,y)=3(x+y)+32xy f(x,y)=3(x+y)-32xy f(x,y)=3(x+y)-16xy f(x,y)=3(x+y)+16xy
f(x,y)=3(x+y)+32xy f(x,y)=3(x+y)-32xy f(x,y)=3(x+y)-16xy f(x,y)=3(x+y)+16xy
若x,y∈R且x2+y2≠0,则x,y全不为0 若x,y∈R且x2+y2≠0,则x,y不全为0 若x,y∈R且x,y全为0,则x2+y2=0 若x,y∈R且xy≠0,则x2+y2≠0
f(x,y)=3(x+y)+32xy f(x,y)=3(x+y)-32xy f(x,y)=3(x+y)-16xy f(x,y)=3(x+y)+16xy
f(x,y)=3(x+y)+32xy f(x,y)=3(x+y)-32xy f(x,y)=3(x+y)-16xy f(x,y)=3(x+y)+16xy
若X→Y,Y→Z,则X→Z 若X→y,且Y→CY,则X→Y, 若X→Y,X--Z,则X→YZ 若XY→Z,则X→Z,Y→Z
若X→Y,Y→Z,则X→Z 若X→Y,且
,则X→Y’ 若X→Y,X→Z,则X→YZ 若XY→Z,则X→Z,Y→Z
y3<y2<y1 y1<y2<y3 y2<y1<y3 y2<y3<y1