计算行列式[tex=10.786x4.786]TIwZYBkNsy31H1RNd/OloAUgRcBeh8P/K8CKPLvBg47hhBlyssxX8HZc0zWoyE9NCfDaaDsb1cNeJ8XJT5+rr4L7nFdFZbRsYkYIObmDMHWVC63FPkV92xy3hUnnRqRlpLmqvSrisrB9dD5QfGxVd+2EYFTNxDDCe8+XkIF9WzI=[/tex].

求证[tex=6.357x4.786]xbOkdWXE1V4xsD8dsMow0p6Qf+FUnh6GtG9NMPEeZ7KpxIt9agaU03HU1o3YKvuQbkCoKp212IlvzLOPLbDT0gMEYVwF+hiJ9DBEQqqXMDBhE1CAaTZUoGsVwoPTje4X[/tex][tex=10.786x4.786]e9VVZm5cFfe4EsoF7gV2Ppj2IWgKN7B+OOTQno4zGjvf/VwC34bpD7MlwgdyANWijaUuFmFWrifEhFzjLX5S+xD+UxCdRsW1PxWXOpX9kb4DtDAcWQbvBSZjAQDnlidz[/tex]

计算行列式[tex=10.786x4.786]rD0fTcokqUjPlLOdGMIUmyoOYePR6ZzWzOjNCpBqc6TXaNs1SnGk3HtU6VzhaSMaE52MzUxnM/yH/JfKT3KnakAs6gQcL9rMTZ8aM2IyP9SaDrzoIFpggrFnOQ0qc71jkfpS7OT/EcJQVhYn3KMQwPVWu/o9AhprmbMgyO29eog=[/tex]的值.

设行列式[tex=10.786x4.786]rD0fTcokqUjPlLOdGMIUm7mq1RTRHtPy7Wug9s1DfLQ9op9JVvUnXTBi6UXyh6Bnp9ir0U3cnEHTSpnTJgz9rTmALvqXXbviQigUm3DiuY+9Qf7jEZsw2rumqD4fnnibx6THwdaI4Xcj4RnM7ckiza7/XkrOOyhqrSFQ8kOCmfo=[/tex]，则[tex=10.214x1.214]tZ5glh8Hm9Z0hzgwAsKRwDIlVGiMMAzcJOGYoV0iesgoya4I+9bHMOHm24dv2jkw[/tex][input=type:blank,size:4][/input].

下列变量组（）是一个闭回路。 A: {x，x，x，x，x，x} B: {x，x，x，x，x} C: {x，x，x，x，x，x} D: {x，x，x，x，x，x}

以下谓词蕴含式正确的是（）: (∀x) (A(x)→B(x))=>( ∀x)A(x)→(∀x)B(x)|(∀x) (A(x)↔B(x))=>( ∀x)A(x)↔(∀x)B(x)|(∀x)A(x)∨(∀x)B(x)=>( ∀x) (A(x)∨B(x))|(∃x) (A(x)∧B(x))=>(∃x)A(x)∧(∃x)B(x)

以下谓词蕴含式正确的是（）: (?x) (A(x)→B(x))=>( ?x)A(x)→(?x)B(x)|(?x) (A(x)?B(x))=>( ?x)A(x)?(?x)B(x)|(?x)A(x)∨(?x)B(x)=>( ?x) (A(x)∨B(x))|(?x) (A(x)∧B(x))=>(?x)A(x)∧(?x)B(x)

下列式中错误的是： A: (∀x)(A(x)Úp(x)) Û (∀x)A(x)Ú (∀x)p(x) B: ($x)A(x) Ù p Û ($x)(A(x) Ù p ) C: (∀x)(A(x)ÚB(x)) Þ (∀x)A(x)Ú( ∀x)B(x) D: ($x)(A(x)ÙB(x)) Þ ($x)A(x)Ù( $x)B(x)

判断下列推证是否正确。 (∀x)(A(x)→B(x))⇔(∀x)(￢A(x)∨B(x)) ⇔(∀x)￢( A(x)∧￢B(x) ) ⇔￢(∃x) ( A(x)∧￢B(x) ) ⇔￢( (∃x)A(x)∧(∃x)￢B(x) ) ⇔￢(∃x)A(x)∨￢(∃x)￢B(x) ⇔￢(∃x)A(x)∨(∀x)B(x) ⇔(∃x)A(x)→(∀x)B(x)

以下谓词公式中，( )不是逻辑有效式。 A: ($x)(P(x)∧Q(x)) Þ ($x) P(x)∧($x) Q(x) B: ("x)(P(x)∧Q(x)) Þ ("x) P(x)∧("x) Q(x) C: ($x)(P(x)∧Q(x)) Û ($x) P(x)∧($x) Q(x) D: ("x)(P(x)∧Q(x)) Û ("x) P(x)∧("x) Q(x)