Re: adjective noun first order logic

On Dec 6, 8:24 am, Keenlearner <yin...@xxxxxxxxx> wrote:
Thanks for the reply, actually I was thinking to write "John is an old
man", but I thought that will give raise of existential quantifier,
because I want it to be simpler. Why is there not existential
quantifier for "John is an old man" ? Thank you.

On Dec 6, 5:23 am, David Ullrich <ullr...@xxxxxxxxxxxxxxxx> wrote:



Keenlearner wrote:
I am doing natural language processing research, I was wondering which
is the correct way of representing "old man John" in first order
predicate calculus, later on this logic will be converted into Prolog
clauses.

old(john) ^ man(john)

old(john) => man(john)

man(john) => old(john)

if you think one is wrong or right please tell me why ?! Thank you
very very much.

None of those is a correct "representation" of "old man John",
because they are all (representations of) _assertions_, and
"old man John" is not an assertion.

If ^ means "and" then "old(John) ^ man(John)" is a correct
representation of the _assertion_ "John is an old man".
That's not the same thing.- Hide quoted text -

- Show quoted text -

You need no existential quantifier because you need to use no
variables at all. As you said, John is a constant.
.

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