【单选题】
设M(x):x是人;F(x):x要吃饭。用谓词公式表达下述命题:所有的人都要吃饭,其中错误的表达式是( )
①
<imgwidth="118"height="20"src="../uploadfiles/word/lsss001.files/image015.png">
②
<imgwidth="128"height="20"src="../uploadfiles/word/lsss001.files/image016.png">
③
<imgwidth="111"height="20"src="../uploadfiles/word/lsss001.files/image017.png">
④
<imgwidth="122"height="20"src="../uploadfiles/word/lsss001.files/image018.png">
【单选题】
设A(x):x是人,B(x):x犯错误,命题“没有不犯错误的人”符号化为( )
①
<imgwidth="98"height="20"src="../uploadfiles/word/lsss002.files/image014.png">
②
┐<imgwidth="68"height="20"src="../uploadfiles/word/lsss002.files/image015.png">┐B(x))
③
┐<imgwidth="96"height="20"src="../uploadfiles/word/lsss002.files/image016.png">
④
┐<imgwidth="63"height="20"src="../uploadfiles/word/lsss002.files/image017.png">┐B(x))