I have a silly question.
I’m trying to solve some exercises that have to do with the walrasian demand function $x(p,w)$ and excess demand function $z$.
More especifically, I’m asked to show that there is not a price vector ($p$ belongs to the simplex) such that $z(p)=0$ when $z$ is not continuous for all goods. As $z$, for a given good $i$, is the sum of the walrasian demand and a given endowment, I think that the previous statement is the same as saying that if $x(p,w)$ is not continuous then there is not $p$ s.t $z(p)=0$.
Any hint about why, if $z$ or $x$ aren’t continuous then $p$ doesn’t exist?