Exercise Syntax of Predicate Logic

Formulae without variables

For the following exercises we use names and properties from the The Lord of the Rings novels.

Names: frodo, sam, gandalf, aragorn
1-place predicates: hobbit, wizard
2-place predicates: know, help

1 Click on the items that are well-formed expressions of the semantic representation language.

	gandalf
	hobbit
	sauron
	frodo ∧ gandalf
	know(gandalf)
	help(aragorn,frodo)

2 Click on the expressions that are well-formed formulae.

	hobbit
	frodo
	hobbit(aragorn)
	hobbit(frodo) ∧ wizard(gandalf)
	hobbit(frodo) ¬ wizard(sam)

---

The following material is an adapted form of material created by student participants of the project e-Learning Resources for Semantics (e-LRS).
Involved participants: Lisa, Marthe, Elisabeth, and Isabelle.

2. a) Which of the following expressions of predicate logic are formulae? Give an explanation for your decision. If the expression is not a formula try to change it into one. To check your answers click on single expressions.

* family dog

* blonde(Alice,Paul)

* father-of-someone(Alice,Lisa)

* tall(Alice)

* enjoy-watching-football-together

For a general explanation of formulae Click here

Formulae with variables

For the following exercises we use names and properties from the The Lord of the Rings novels.

Names: frodo, sam, gandalf, aragorn
1-place predicates: hobbit, wizard
2-place predicates: know, help

1 Click on the items that are well-formed expressions of the semantic representation language.

	y
	x ∧ frodo
	∃x

2 Click on the expressions that are well-formed formulae.

	∀x (hobbit(x) ⊃ x = gandalf)
	∃y(hobbit(x) ∨ wizard(gandalf))

---

Back to

• the exercises for chapter 2
• the material for chapter 2
• the overview over all chapters