Can anyone please translate this Predicate Logic statement into English? The question is this:
Let $\mathbb{N}$ be the set on Natural numbers. Let $S=\{1,8,4\}$ and $T=\{6,8,11\}$.
Which of the following statements are correct?
$∃ x. ∀ y. (x ∈ T \land y ∈ T) \land (x ≤ y ∧ x ∈ S)$
I read it as:
There exists an $x$ for all $y, x$ is in the set $T$ and $y$ is in the set $T$ and there exists an $x$ that is less than or equal to $y$ and $x$ is in the set $S$.
The correct answer was False.
I interpreted this as meaning for every single value of $y$ there is a value of $x$ that is less than or equal to $y$ and every value of $x$ is also in the set $S$.
Is this correct?
Yes, it is false, indeed.
Witness that $8$ is the only element in the intersection of $S,T$, and that this is greater than $6$, an element in $T$. Thus disproving by counterexample.
More so, witness that $1964$ is not in $T$; so not every $y$ is in $T$ even if there exists an $x$ in $S\cap T$.
$∃x.∀y.(x∈T∧y∈T)∧(x≤y∧x∈S)$
"There is some $x$ such that $x$ is in $T$ and $S$ and every $y$ is in $S$ and at least as great as the $x$."