设R(x):x是兔子,T(y):y是乌龟,Q(x , y):x比y跑得快,命题“兔子比乌龟跑得快”符号化为( )。
A: ∀x(R(x)→Q(x,y))
B: ∀x(R(x)→∃y ( T(y) ∧Q(x,y) ) )
C: ∀x∃y (R(x) ∧ T(y) ∧Q(x,y) )
D: ∀x∀y (R(x) ∧ T(y) →Q(x,y) )
A: ∀x(R(x)→Q(x,y))
B: ∀x(R(x)→∃y ( T(y) ∧Q(x,y) ) )
C: ∀x∃y (R(x) ∧ T(y) ∧Q(x,y) )
D: ∀x∀y (R(x) ∧ T(y) →Q(x,y) )
举一反三
- 设P(x):x是大象,Q(x):x是老鼠,R(x,y):x比y重,则命题“大象比老鼠重”的符号化为 A: ∀x∀y(P(x)∧Q(y)→R(x,y)) B: P(x)∧Q(y)→R(x,y) C: ∀x∃y(P(x)∧Q(y)∧R(x,y)) D: ∃x∃y(P(x)∧Q(y)∧R(x,y))
- 【单选题】公式(∀x)[P(x)∧Q(x, A) →(∃y)[R(x, y)∨S(y)]]中,∀x的辖域为 , ∃y的辖域为 。 A. P(x); R(x, y) B. P(x)∧Q(x, A); R(x, y) C. P(x)∧Q(x, A)→(∃y)[R(x, y)∨S(y)]; R(x, y) D. P(x)∧Q(x, A)→(∃y)[R(x, y)∨S(y)]; R(x, y)∨S(y)
- 与公式("x)(P(x)∧Q(x, y))Þ($x)R(x, y)等值的是( )。 A: ("x)(P(x)∧Q(x, z))Þ($x)R(x, y) B: ("y)(P(y)∧Q(y, y))Þ($x)R(x, y) C: ("z)(P(z)∧Q(x, y))Þ($x)R(x, y) D: ("u)(P(u)∧Q(u, z))Þ($x)R(x, z)
- 【单选题】与公式("x)(P(x)∧Q(x, y))Þ($x)R(x, y)等值的是()。 A. ( " x )( P ( x ) ∧ Q ( x , z )) Þ ( $ x ) R ( x , y ) B. ( " y )( P ( y ) ∧ Q ( y , y )) Þ ( $ x ) R ( x , y ) C. ( " z )( P (z ) ∧ Q ( x , y )) Þ ( $ x ) R ( x , y ) D. ( " u )( P ( u ) ∧ Q ( u , z )) Þ ( $ x ) R ( x , z )
- 谓词公式∀xP(x)→∀xQ(x)∨∃yR(y)的前束范式为 A: ∀x∀z∃y(P(x)→Q(z) ∨ R( y)) B: ∃x∀z∃y(P(x)→Q(z) ∨ R( y)) C: ∀x∃y(P(x)→Q(x) ∨ R( y)) D: ∃x∀y(P(x)→Q(x) ∨ R( y))