Recent submissions

Comment · 5 years ago
I think the general program of categorical logic, the work of Lambek and Scott, and J. Bell on topos theory and local set theory really make clear the relationship between category theory and logic, as well as lambda calculus.

A topos is essentially a cartesian closed category with a subject classifier. In Set this is the two element set of 1/0 which is a Boolean algebra and thus the internal logic of the category Set is classical.

In general though the subobject classifier is a heyting algebra which expresses the semantics of intuitionistic logic.

There is also a very good, but introductory, book by Goldblatt on Topoi that covers this logical aspect

So in terms of logics the category of Sets is the exception.

By internal logic I mean that for every topos one builds up a theory using it's objects and function between them. An equivalence theorem (see J. Bell) states that a given topos is essentially equal to the category generated by this internal theory.

This program began with Lawvere who noticed that conjunction and implication were really adjoints, the same one as between the product and hom functors in a cartesian closed category.

Comment · 5 years ago
Comment · 7 years ago
> Of course a problem was that in 1984 the modern importance of free software wasn't really apparent.

Perhaps it wasn't apparent widely, but it was certainly clear to MSFT and IBM. IBM lawyers at the time refused to allow RMS to come speak at the Watson lab where I worked, because of his ideas about free software.

Comment · 7 years ago
Comment · 8 years ago
Comment · 9 years ago
According to Bloomberg, margin requirements are going to be quite high in order to keep bitcoin trading from creating issues.

If you can trade bitcoin futures in Chicago, to me that says regulation is coming, and even central bank involvement. Seems to go against the grain of what bitcoin pretends to be about.

Comment · 9 years ago
#2. Exactly, seems to me an academic kind of thing, he helped them a lot, a little attribution would not have hurt, and the lawyers could have easily been told to pipe down.

#3. It does offer the maximum freedom to some potential users, but no responsibilities to extend those freedoms to others. In my opinion this is why the GPL truly extends the maximum amount of freedom to everyone, users, lusers, abusers, and just plain old hackers.

Comment · 9 years ago
yes, revocable and irrevocable trusts, combined with solid powers of attorney, living wills, etc..

Trusts essentially keep estates out of probate. Since it's the money these criminals are after they work well towards that goal.

Comment · 9 years ago
estate planning
Comment · 9 years ago
It's all down hill from here. Pretty soon there will be a 2K word minimum and we'll all be making up stuff, like those fifth grade book reports.
Comment · 9 years ago
gotta love this line:

"We aim to be a drop-in replacement with bug-for-bug compatibility."

Live from the official Hacker News API

A modern reader for Hacker News · SvelteKit + Skeleton