Closed Nikk-l closed 2 months ago
In chapter 35, on page 295 of the printed version, the symmetric relation is symbolized as:
$$[\forall x\forall y(R(x,y) \rightarrow R(y,z))]$$
I think there has been an error in introducing the free variable $z$, as emphasized by the box just above this symbolization, and it was rather meant to be defined as:
$$[\forall x\forall y(R(x,y) \rightarrow R(y,x))]$$
This same error also shows itself in the practice exercise B of the same chapter.
Good catch, thanks!
rzach
commented
2 months ago
In chapter 35, on page 295 of the printed version, the symmetric relation is symbolized as:
$$[\forall x\forall y(R(x,y) \rightarrow R(y,z))]$$
I think there has been an error in introducing the free variable $z$, as emphasized by the box just above this symbolization, and it was rather meant to be defined as:
$$[\forall x\forall y(R(x,y) \rightarrow R(y,x))]$$
This same error also shows itself in the practice exercise B of the same chapter.