Creation of the World
The real world
At the time Alice, Paul, Tom and Lisa live in Berlin, but they rather want to live in Munich. Alice is married to Paul. They are Tom and Lisa's parents. Both Lisa and her father are tall, while Alice and Tom are rather small. Lisa and her mom share the same hair color, which is blonde. The family enjoys watching American football games together. But while the girls also like watching soccer, the boys get bored of it. Walter, the family's dog, doesn't care about sports at all, he likes to eat their shoes.
Comment Sailer: Very nice text! I don't think the referent of their is clear in the last sentence. Maybe you can put everybody's shoes or something similar there instead.
1. Take a look at the story above. Using predicate logic terms and notation we now want to define the world described in the story. First we need our individuals, their relations and possible properties. You will need a pen and paper to write down your answers!
Note: In the Introduction course the expressions of the World were colored green and the expressions of predicate logic orange. As colors are not used in the Wiki the expressions of the World will be written in bold and the ones of the predicate logic in italic.
Comment Sailer:
1) You could use color in the wiki: <span style="color:red">text in red</span> to create text in red, and similarly for green.
2) In the textbook the use of fonts is just the other way around, so it would be better if you either use colors or you use bold for constants from predicate logic, italic for the element from the world.
a.) Define the universe described in the “Real World Scenario”. Make sure you use the correct notation.
b.) Choose three individuals from those mentioned in the story and map them to 3 properties mentioned in the story. Don't forget: empty sets are possible!
c.) Write down the possible relations mentioned in the story and map them to the individuals you wrote down in a.
d.) Write down the I-functions (interpretation functions) for a, b and c.