Exercise-ch2: Difference between revisions

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Line 15: Line 15:
+ '''gandalf'''
+ '''gandalf'''
+ '''hobbit'''
+ '''hobbit'''
- '''frodo''' ∧ '''gandalf'''
|| The connectors "∧" and "∨" can only be used to combine two formulae.
- ∃''x''
- ∃''x''
|| A quantifier, ∀ or ∃, can only be used with a variable and a formula. For example: ∃''x''('''hobbit'''(''x''))
|| A quantifier, ∀ or ∃, can only be used with a variable and a formula. For example: ∃''x''('''hobbit'''(''x''))
Line 26: Line 28:
- '''frodo'''
- '''frodo'''
+ '''hobbit'''('''aragorn''')
+ '''hobbit'''('''aragorn''')
- '''frodo''' ∧ '''gandalf'''
+ ∀''x'' ('''hobbit'''(''x'') ⊃ x = '''gandalf''')
+ ∀''x'' ('''hobbit'''(''x'') ⊃ x = '''gandalf''')
+ ∃''y''('''hobbit'''(''x'') ∨ '''wizard'''(''gandalf''))
+ ∃''y''('''hobbit'''(''x'') ∨ '''wizard'''(''gandalf''))

Revision as of 19:46, 15 March 2013

Additional Exercises for Chapter 2: Predicate Logic

Formulae

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
2-place predicates: know, help

  

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

gandalf
hobbit
frodogandalf
x
know(gandalf)

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

hobbit
frodo
hobbit(aragorn)
x (hobbit(x) ⊃ x = gandalf)
y(hobbit(x) ∨ wizard(gandalf))