1.Which Boolean formula is not a tautology??
A.(A=>B)=>(B=>A)
B.A=>(~A=>B)
C.(A=>A)=>(B=>B)
2.在布林代数中，xyz+x'y'z+xy'z'+x'yz'=?
A. x ⊕ y ⊕ z
B. x'⊕ y ⊕ z
C. x ⊕ y'⊕ z
D. x ⊕ y ⊕ z'
3.正逻辑的AND闸 相当于负逻辑的OR闸
why= =?? 为啥不是NAND??
4.xz+x'yz = z(x+x'y)
= z(x+x')(x+y) <==这里开始看不懂 为啥(x+x'y)可以拆成(x+x')(x+y)??
= z(x+y)
= zx+yz
谢谢大家!