$1.(5)$ What is meant by the "aboutness" of language $--$ and how is this

formalized in FOL semantics? $($As always, be brief!$)$

$2.(5)$ What role does truth play in analyzing the trustworthiness of rules

of inference?

$3.(5)$ Mention two of kinds of "know$-$how" $($skills$)$ that $($at least some$)$

people have that arguably would not be easy to represent in FOL,

and probably not useful in that form in any case. Choose a mental

skill and a physical skill, as different as you can from any mentioned

in class$/$notes$.$

$4.$ a$.(2)$ In what respect is the concept of a first$-$order LANGUAGE more

specific than the concept of first$-$order LOGIC?

b$.(8)$ Which of the following expressions $($i$)$ can be VARIABLE$-$FREE well$-$

formed terms in a first$-$order language, which ones $($ii$)$ can be well$-$

formed formulas WHOSE VARIABLE OCCURRENCES, IF ANY, ARE ALL BOUND BY

QUANTIFIERS, and which ones $($iii$)$ cannot be either of these? Adhere

to the syntactic conventions that have been stipulated in this course

$($ignoring the B&L text$)$; for cases of $($iii$),$ give a quick reason:

$-$ USA

$-$ Neighbor$-$of$($USA$,$Canada$)$

$-$ northern$-$neighbor$-$of$($USA$)$

$-$southern$-$neighbor$-$of$($USA$,$Canada$)$

$-($A $=>$ B$)$

$-($A $=$ B$)($B $=$ C$)=>($A $=$ C$)$

$-($x $($P$($x$)=>$ Q$($x$)))($y $($y $=$ x$))$

$-(($Happy$($Snoopy$)$ Dog$($Snoopy$))=>$ Happy$($Dog$($Snoopy$)))$