Re: [Hol-info] rigorous axiomatic geometry proof in HOL Light

2012-08-12 Thread Michael Norrish
On 11/08/2012, at 17:05, Bill Richter wrote: > My main problem is that I don't understand HOL, so I don't know what theorems > HOL Light is proving for me. The HOL4 Logic manual looks like a very > respectable CS document, but I haven't been able to read it yet, and it's not > a HOL Light do

Re: [Hol-info] rigorous axiomatic geometry proof in HOL Light

2012-08-12 Thread Mark
Hi Bill, There are a few points which you may or may not already realise. Sorry if these are obvious, but I haven't been following the (very lengthy!) thread in detail. 1. Just checking you understand this: In HOL Light and HOL4 (but not ProofPower HOL), sets are represented as functions to boo

Re: [Hol-info] rigorous axiomatic geometry proof in HOL Light

2012-08-12 Thread Mark
Hi Bill, > ... My main problem is that I don't understand HOL, so I don't know what > theorems HOL Light is proving for me. The HOL4 Logic manual looks like > a very respectable CS document, but I haven't been able to read it yet, and > it's not a HOL Light document. And it's not a particularly

Re: [Hol-info] rigorous axiomatic geometry proof in HOL Light

2012-08-12 Thread Bill Richter
Thanks, Michael! I will treat the Logic Manual as a true description of the HOL in HOL Light, and I will try harder to read it. I have a lot of trouble with your 3 sentences: Sets in HOL Light and HOL4 are predicates over their respective types. Types correspond to non-empty sets (as a

Re: [Hol-info] rigorous axiomatic geometry proof in HOL Light

2012-08-12 Thread Bill Richter
Thanks, Mark! I looked at Tom Hales's Notices article, as you suggested www.ams.org/notices/200811/tx081101370p.pdf Now Tom is a great mathematician (he's the main reason I'm here), but Tom is now an HOL Light expert, and I think mathematicians can't be expected to understand him. He starts ou

Re: [Hol-info] rigorous axiomatic geometry proof in HOL Light

2012-08-12 Thread Michael Norrish
On 13/08/12 14:17, Bill Richter wrote: > Thanks, Michael! I will treat the Logic Manual as a true description of the > HOL in HOL Light, and I will try harder to read it. I have a lot of trouble > with your 3 sentences: >>Sets in HOL Light and HOL4 are predicates over their respective types.

Re: [Hol-info] rigorous axiomatic geometry proof in HOL Light

2012-08-12 Thread Michael Norrish
On 13/08/12 14:53, Bill Richter wrote: > That sounds great, but here I want more details: > > The types are presented in the HOL Light System box. > > Terms are the basic mathematical objects of the HOL Light system. The > syntax is based on Church’s lambda-calculus [to define functions

Re: [Hol-info] rigorous axiomatic geometry proof in HOL Light

2012-08-12 Thread Mark
Hi Bill, It's important to understand that the HOL4 Logic Manual gives a (more-or-less) formal semantics of a formal logic. That's two levels of formal! None of the set theory given in this document is actually part of the HOL logic itself. Rather the set theory is a formal way of portraying to

Re: [Hol-info] rigorous axiomatic geometry proof in HOL Light

2012-08-12 Thread Mark
Hi Bill, > Isn't this supposed to be about sets? No, HOL is about types. Tom is informally explaining what the HOL logic is, rather than explaining it in terms of some other formal notation (e.g. ZFC set theory). > Can you explain how the set abstraction/enumerations of sets.ml are lambdas? It