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muraiki

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muraiki
·3 か月前·議論
When you write a recursive function, Lean’s kernel requires a termination proof, unless the function is a partial or marked as unsafe. In those cases, they can’t be used in proofs. https://lean-lang.org/doc/reference/latest/Definitions/Recur...
muraiki
·4 か月前·議論
Oh whoops, thank you for the correction! I didn't realize that.
muraiki
·4 か月前·議論
The article says that AWS's Cedar authorization policy engine is written in Lean, but it's actually written in Dafny. Writing Dafny is a lot closer to writing "normal" code rather than the proofs you see in Lean. As a non-mathematician I gave up pretty early in the Lean tutorial, while in a recent prototype I learned enough Dafny to be semi-confident in reviewing Claude's Dafny code in about half a day.

The Dafny code formed a security kernel at the core of a service, enforcing invariants like that an audit log must always be written to prior to a mutating operation being performed. Of course I still had bugs, usually from specification problems (poor spec / design) or Claude not taking the proof far enough (proving only for one of a number of related types, which could also have been a specification problem on my part).

In the end I realized I'm writing a bunch of I/O bound glue code and plain 'ol test driven development was fine enough for my threat model. I can review Python code more quickly and accurately than Dafny (or the Go code it eventually had to link to), so I'm back to optimizing for humans again...
muraiki
·3 年前·議論
> Research has long shown that layoffs have a detrimental effect on individuals and on corporate performance. The short-term cost savings provided by a layoff are often overshadowed by bad publicity, loss of knowledge, weakened engagement, higher voluntary turnover, and lower innovation — all of which hurt profits in the long run. To make intelligent and humane staffing decisions in the current economic turmoil, leaders must understand what’s different about today’s larger social landscape. The authors also share strategies for a smarter approach to workforce change.

https://hbr.org/2022/12/what-companies-still-get-wrong-about...
muraiki
·9 年前·議論
You said: "...profitable majors, so you'd probably see a lot more STEM degrees and a lot fewer of everything else...". In terms of lifetime earnings, STEM is not necessarily a sure fire route:

"'Students and parents have a pretty good idea of what majors pay the most, but they have a poor sense of the magnitude of the differences within the major,' said Douglas A. Webber, an associate professor of economics at Temple University who studies earnings by academic field. He points to one example: The top quarter of earners who majored in English make more over their lifetimes than the bottom quarter of chemical engineers.

But what if you never make it to the top of the pay scale? Even English or history graduates who make just above the median lifetime earnings for their major do pretty well when compared to typical graduates in business or a STEM field."

See https://www.nytimes.com/2017/11/03/education/edlife/choosing...
muraiki
·12 年前·議論
There are differences between the understanding of redemption in the Catholic and Orthodox churches; I can speak only for the Orthodox part, and hopefully I won't mangle it somehow. :) I've tried to compress this as much as possible without being confusing.

The goal of humanity is not simply to end up in Heaven, to reach some sort of place. It is not even necessarily the case that we are trying to restore ourselves to the state that Adam and Eve had -- for even they made a mistake at that time, a mistake serious enough to have cosmic ramifications.

So what was the problem? Well we do know of Adam and Eve being cast from Paradise after eating the fruit of the Tree of Knowledge of Good and Evil. But it's not the eating of the apple that begins the story. Rather, it was Adam's reaction to God. When God confronted Adam, Adam did not respond by saying, "Yes, I ate of the tree against Your warning. I'm sorry; please forgive me." He said instead, "The woman which You gave me, she made me eat it." Instead of being accountable for his action, for his own free will, Adam blames not only Eve but his Creator, essentially renouncing his free will. It was this act, that of failing to accept responsibility and instead casting down his neighbor, that led to humanity being cast out from Paradise -- or rather, casting itself out. Adam's action had effects throughout the cosmos, sending everything into disorder and brokenness and death.

So we see that the problem we have is that humans are cruel to one another and to God (and to creation, also). And this cannot be rectified in a way like having a bone fixed or some code swapped, for the problem is inextricably tied up in humanity's free will. So God chose to rectify this in a way that demonstrated not only His divinity, but _perfect humanity_. Christ becomes incarnate in the flesh and demonstrates, Himself, not only what it is to be truly human but that glory which all humanity is intended to receive. St. Athanasius describes this succinctly as: "God became man so that man might become God." This concept is termed theosis.

Theosis is realized in love of God and one's neighbor, actualized through humility. Unlike Adam blaming Eve, Christ, the new Adam, blames Himself. Christ takes up and covers the sin of the world, even on the Cross praying, "Father, forgive them, for they know not what they do." Christ accounts _only Himself_ as deserving of death, and all as worthy of eternal life. And in this perfect love, even death has no power over Him. Hades (a place of gloom where the dead were consigned; a jail in a sense -- not Hell) cannot contain Him and is destroyed, and those who were bound there by Adam's sin are released. "Christ is Risen from the dead, trampling down death by death, and upon those in the tombs bestowing life." It through these actions that all of creation was redeemed.

Yes, that was "redemption" in the past tense. From the Orthodox perspective, redemption has already occurred because Christ has not only rectified the division between God and man, He has given us the tools to experience divine life even now, through humble love of God and neighbor. Christ has given us the perfect example of how to live, He has destroyed death, and through Christ's union with humanity in the Incarnation, descent into Hades, Resurrection, and Ascention, paved the way to become by grace that which God is by nature.

"The powerlessness of Christ has always threatened the powerfulness of the world. And the silence of the cross is the most eloquent sermon about the power of love. Despite what we know in ourselves and whatever we see in our world, the cross proclaims what love can and will achieve. The scandal of the cross is that, in spite of our wrongs and the wrongdoings of our world, God loves us to the point of death." --Fr John Chryssavgis, Light Through Darkness: the Orthodox Tradition