Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Bill Richter
Thanks, Konrad! You seem to agree with me here, that the typed-LC-implies-FOL isn't actually important: My personal feelings on this foundational aspect are that the actual set of axioms isn't that important provided the usual introduction and elimination rules of predicate calculus

Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Mark Adams
Hi Bill, Have you tried looking at the HOL Zero source code? I think you will find it illustrative for your purposes. It has a simple core like HOL Light, but the source code explains more of what is going on. In file 'corethy.ml' I try to motivate the axioms and constant definitions used in

Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Mark Adams
Hi Bill, on 21/3/14 6:19 AM, Bill Richter rich...@math.northwestern.edu wrote: ... T = ((λxbool . x) = (λxbool . x)) So it looks to me that HOL Light is defining Tom's primitive = in terms of the Ocaml =. Is that correct? And maybe that just means that the HOL Light primitive = is

Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Konrad Slind
Bill: On p 29 of LOGIC, you write that there are constants Tbool, ∀(α→bool)→bool etc. Why aren't there colons? I would have written that as T:bool and ∀:(α→bool)→bool Are the apparent subscripts supposed to indicate colons, or does HOL4 not use colons for type annotations? Throughout the

Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Bill Richter
Thanks, Konrad! I'll read your proof of NOT_FORALL_THM, and try to find Gordon and Melham's book. Two points: I don't believe that Church ever explained how typed LC implies FOL. Church certainly does not explain this in his paper A Formulation of the Simple Theory of Types

Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Bill Richter
Thanks for correcting me, Mark! I'll look at your HOL Zero source code, especially corethy.ml. I see my error now. From bool.ml: let T_DEF = new_basic_definition `T = ((\p:bool. p) = (\p:bool. p))`;; The first = is an Ocaml =, but the 2nd =, the one we care about, is the primitive HOL

Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Ramana Kumar
The constant = is not defined in HOL Light, but simply declared (as Mark said). In fact, equality is even more basic than that: it's a built in term. You can see, for example, the safe_mk_eq function in fusion.ml, and also the the_term_constants reference (which starts with = built in). I feel

Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Mark Adams
I should have said '@' instead of '?' here. The constant '?' is actually defined in these axiomatisations (using '@'). Mark. on 21/3/14 9:10 AM, Mark Adams m...@proof-technologies.com wrote: ... In HOL Light's axiomatisation, the only such entities are the 'bool' and 'fun' type constants and

Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Mark Adams
Hi Bill, on 21/3/14 4:28 PM, Bill Richter rich...@math.northwestern.edu wrote: ... BTW where is the constant = defined in HOL Light? I see now that the line in bool.ml override_interface (=,`(=):bool-bool-bool`);; just means that = is being defined as a synonym for = in this special case.

Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Andrew Butterfield
On 20 Mar 2014, at 16:50, Rob Arthan r...@lemma-one.com wrote: ProofPower is no different from HOL4 and HOL Light as regards substitution. The ProofPower documentation does include a formal specification of the logic and the proof system, but you would probably do better looking at the

[Hol-info] NLSR: 2nd call for papers

2014-03-21 Thread Walther Neuper
[Apologies for multiple copies] SECOND CALL FOR PAPERS FOR NATURAL LANGUAGE SERVICES FOR REASONERS (NLSR) http://vsl2014.at/meetings/NLSR-index.html July 18, 2014 Affiliated with affiliated to RTA-TLCA

Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Andrew Butterfield
On 20 Mar 2014, at 16:50, Rob Arthan r...@lemma-one.com wrote: ProofPower is no different from HOL4 and HOL Light as regards substitution. The ProofPower documentation does include a formal specification of the logic and the proof system, but you would probably do better looking at the

[Hol-info] Set-theoretical interpretation of HOL [Was: Learning HOL Light]

2014-03-21 Thread Ian Zimmerman
On Fri, 21 Mar 2014 09:13:41 + Andrew Butterfield andrew.butterfi...@scss.tcd.ie wrote: Is this the document kanananaskis-9-logic.pdf? If it is, I have a query: in Sec 1.1 Introduction (p9) we are shown some properties One is *Inhab* : U does not contain empty sets - fair enough

Re: [Hol-info] Learning HOL Light

2014-03-21 Thread Rob Arthan
Andrew, On 21 Mar 2014, at 09:13, Andrew Butterfield andrew.butterfi...@scss.tcd.ie wrote: On 20 Mar 2014, at 16:50, Rob Arthan r...@lemma-one.com wrote: ProofPower is no different from HOL4 and HOL Light as regards substitution. The ProofPower documentation does include a formal

[Hol-info] How LC implies FOL

2014-03-21 Thread Cris Perdue
On Fri, Mar 21, 2014 at 9:08 AM, Bill Richter rich...@math.northwestern.edu wrote: Thanks, Konrad! I'll read your proof of NOT_FORALL_THM, and try to find Gordon and Melham's book. Two points: I don't believe that Church ever explained how typed LC implies FOL. Church certainly does not