From: alex goldman on
I'm interested in learning more about higher-order logic: its computational
aspects, inference and learning algorithms, and perhaps uncertainty
representation.

The books on higher-order logic that I found appear to actually be tutorials
on using specific proof assistance software products (HOL or Isabelle),
which is not what I want.

Does anyone have any suggestions or links to resources? (No research paper
plugs please, however)
From: Jose Juan Mendoza Rodriguez on

alex goldman wrote:

> I'm interested in learning more about higher-order logic
> (...)
> Does anyone have any suggestions or links to resources?

This is a very readable introduction to higher-order
intuionistic logic:

Simon Thompson, 'Type Theory and Functional Programming'
http://www.cs.kent.ac.uk/people/staff/sjt/TTFP/

--
Jose Juan Mendoza Rodriguez

let me=josejuanmr in
let privacy=iespana in
let net=es in
me(a)privacy.net

From: alex goldman on
Jose Juan Mendoza Rodriguez wrote:

>
> alex goldman wrote:
>
>> I'm interested in learning more about higher-order logic
>> (...)
>> Does anyone have any suggestions or links to resources?
>
> This is a very readable introduction to higher-order
> intuionistic logic:
>
> Simon Thompson, 'Type Theory and Functional Programming'
> http://www.cs.kent.ac.uk/people/staff/sjt/TTFP/
>

Thanks. I've read some of it, however, while I asked for pointers to
literature on higher-order logic, this paper discusses first-order logic.
And, while it's not a research paper plug, it does seem to be Constructive
Mathematics advocacy and mainly concerns itself with programming aides,
does it not?

I was hoping to find a non-advocacy review of main results in higher-order
logic (as opposed to first-order logic).

By the way, is the term "higher-order logic" ever used in a sense different
from "second-order logic"? Since second-order logic allows quantification
over relations, would third-, etc. order logics allow quantification over
quantifiers or something similarly outlandish?
From: H. Enderton on
alex goldman <hello(a)spamm.er> wrote:
>By the way, is the term "higher-order logic" ever used in a sense different
>from "second-order logic"? Since second-order logic allows quantification
>over relations, would third-, etc. order logics allow quantification over
>quantifiers or something similarly outlandish?

It's simpler than that.
First order: quantify over individuals
Second order: quantify over sets of individuals and relations on individuals.
Third order: quantify over sets of sets of individuals (and relations on
relations on individuals).

Quibble: Church actually used a slightly more refined way of counting
third, fourth, ... order.

> I'm interested in learning more about higher-order logic
> (...)
>I was hoping to find a non-advocacy review of main results in higher-order
>logic (as opposed to first-order logic).

You said (in the original post) no plugs, so I won't say anything
about Chapter 4 of my logic book.

--Herb Enderton


From: Owen on

"H. Enderton" <hbe(a)sonia.math.ucla.edu> wrote in message
news:ctjns5$hq6$1(a)daisy.noc.ucla.edu...
> alex goldman <hello(a)spamm.er> wrote:
>>By the way, is the term "higher-order logic" ever used in a sense
different
>>from "second-order logic"? Since second-order logic allows
quantification
>>over relations, would third-, etc. order logics allow quantification
over
>>quantifiers or something similarly outlandish?
>
> It's simpler than that.
> First order: quantify over individuals
> Second order: quantify over sets of individuals and relations on
individuals.
> Third order: quantify over sets of sets of individuals (and relations
on
> relations on individuals).

I don't agree.
Second order logic quantifies over properties/relations of individuals,
and so on.
There is no need to specify sets at all.
Only if sets correspond with properties, are you correct.
(there are exceptions: the Russell set does not correspond with any
property)

{x:~(x e x} does not exist!

Third order predications quantify over properties of properties, etc.

>
> Quibble: Church actually used a slightly more refined way of counting
> third, fourth, ... order.
>
>> I'm interested in learning more about higher-order logic
>> (...)
>>I was hoping to find a non-advocacy review of main results in
higher-order
>>logic (as opposed to first-order logic).
>
> You said (in the original post) no plugs, so I won't say anything
> about Chapter 4 of my logic book.
>
> --Herb Enderton
>
>