2. Which of the following is a sentence of PL? (I.e., which s a fromula of PL with no free variables.)
a) (^x)(%y)Lxy>Lyx
b) (^x)(%y)Lxy>(%y)(^x)Lyx
c) (^x)(%y)Lxy>Lyx&(^z)Dz

3. Which of the following is a sentence of PL with the universal quantifier, the upside-down A, as main logical operator.
a) (^x)(%y)(Lxy>Lyx)
b) (^x)(%y)Lxy>Lyx
c) (^x)(%y)Lxy>(%y)(^x)Lyx

4. Which of the following is a substitution instance of (%x)(Bx&Lxb)
a) (%a)(Ba&Lab)
b) (Ba&Lbb)
c) (Ba&Lab)

5. Which of the following is a substitution instance of (^y)(%z)(Tyz&(By>Ly))
a) (Tab&(Ba>La))
b) (^y)(Tyr&(By>Ly))
c) (%z)(Taz&(Ba>La))

Score =
Correct answers: