one question about e hal --ignore or delete the post plz

hi all,

       the verification enviroment has complete and i created the senarios which i could figure out,now i want to check my code style or something with the cadence tool---hal.

       it help me a lot ,but there is one error makes my so confused.

    EAVDNA: Variable xxx is declared, and is written in  at xxx line in yyy.e file but not read.

here is one example in ehal.pdf

:

In the following example, var g is written, but not read:
struct bar_s {
a : int;
foo() is {
var g : int ;
g = a;
};
};
In the following example, var g is both read and written:
struct bar_s {
a : int;
b : int;
foo() is {
var g : int ;
g = a;
b = g;
};
};

i want to ask why??the problem is so usual in my code ,what is the risk?

thank you in advance.

redrabbit.