assertion in first order logic Can anybody give me  an idea how to write this assertion in in first order logic?


  X has not passed one or more of the prerequisites for A. 


Here, X is the name of a person and A is a constant representing a course name.
Expressing properties of elements of the universe in first order logic is mostly achieved through defining appropriate relations. So for this you might like to consider relations like:


$P(x)$ - $x$ is a person,
$C(x)$ - $x$ is a course,
$Pre(x,y)$ - $x$ is a prerequisite of $y$ (note that this doesn't actually say that $x$ and $y$ are courses),
$Pass(x,y)$ - $x$ has passed course $y$.


(The parentheses are just included for clarity - you may have seen different notation where relations are written without.)

Then the rest is just building the logical formula, which in this case should be fairly obvious.


   $notready(x,a) \equiv P(x) \wedge C(a) \wedge \exists y(C(y) \wedge Pre(y,a) \wedge \neg Pass(x,y)) $