1

# Functions in predicate logic.

Thu 20 May, 2010 09:21 am
Could anyone please explain to me how functions work in predicate logic. I am not sure I understand them correctly.

I have several problems involving them

1) U.D. People
Tx: x is friendly
f(x): x's father

And 'No one who is friendly is admired by his/her father'

I got

NOT (]x)(]y)(Lxy & Tf(y))

But that doesn't look right at all

Another one 2)

U.D: People
Tx: x is nice
Lxy: x hits y
f(x): x's sister

And to symbolise - Someone who hits his sister isn't nice

I got

(Vx)(Lxf(x)> NOT Tx)

This isn't for homework but I have a test in a few days and I've been going over some excercises but can't find the answers anywhere. Would really appreciate it if someone could tell me if I am doing this right
• Topic Stats
• Top Replies
Type: Discussion • Score: 1 • Views: 2,936 • Replies: 0
No top replies

### Related Topics

A2K challenge! - Discussion by HexHammer
Logic Proof Help - Question by crimhaze
THE TEN COMMANDMENTS OF LOGIC - Discussion by Ragman
Derivations vs. symbolisation? - Question by collegestudent123
Logic word problem - Question by johnr
Cause of death..... - Discussion by gungasnake
Need help in defining - Question by ichishti
Predicate Logic Help - Question by splenax

1. Forums
2. » Functions in predicate logic.