## Outline of the Testaments Testament -1 - Begins: Jan 1 1930 - Ends: Jan 1 1970 - Church: Untyped and Simply typed - Gödel: General Recursive Functions. - Turing: Automatic Machines. - After dev zero we do etc group. Non-Testament (-½) - Begat list. - Mention McCarthy. - Mention Lisp and Scheme. - Mention various systems. - Begat to Ken. Testament 0 - Begins: Jan 1 1970 - Ends: Sept 17 1991 - The μ part of 0 Testament: Unix & BSD era, C. - The λ part of 0 Testament: ML, System F. - Reverse Mathematics founded by Harvey Friedman in 1975, 1976. Gerald Sacks (from Reminisces of Logicians) was his advisor. - Genesis is Bell Labs Unix. - Exodus is BSD. - Leviticus is ???. - Numbers is Unix wars. - Deuteronomy is GNU. - GNU Project, and was publicly announced on September 27, 1983, on the net.unix-wizards and net.usoft newsgroups by Stallman. Software development began on January 5, 1984, when Stallman did his own Exodus from his job at the Lab so that they could not claim ownership or interfere with distributing GNU components as free software. - GNU never got a functioning kernel (despite lots of hype about Hurd) so GNU software existed in diaspora, forming the core of the userspace of other systems, but never reimplementing the kernel from scratch. - When Ken Thompson was asked how he learned to program, Thompson stated, "I was always fascinated with logic and even in grade school I'd work on arithmetic problems in binary, stuff like that. Just because I was fascinated." Non-Testament (+½) - Begat list. - Everything that will be relevant in (+1) that we didn't cover in (0). - MS-DOS was initially released on August 12, 1981, with the release of PC DOS 1.0 for the IBM PC. Microsoft's version, titled MS-DOS 1.25, was released in August 1982, after Microsoft licensed and adapted the 86-DOS operating system from Seattle Computer Products in July 1981. - Microsoft released Windows in 1985, a year before moving its headquarters to Redmond, Washington. By the late 1980s, Microsoft was the world's largest personal-computer software company. - Python began Dec 1989. - Guido first released it in 1991. - This was Python version 0.9.0. - The "Unix wars" occurred roughly between 1985 and 1995, a period of intense conflict and fragmentation among competing vendors trying to establish a standard for the Unix operating system. The period was marked by numerous Unix variants and the inability to agree on a unified standard, ultimately leading to commercial difficulties for many participants and setting the stage for the rise of free Unix-like systems like Linux. - The Unix shell Bash was launched on June 8, 1989 by Brian Fox as part of the GNU Project. It was created in 1987 as a free software replacement for the Bourne shell (sh). Testament +1 - Begins: Sept 17th 1991 - End of Time (Date): 19 Jan 2038 - End of Days (Date): 03:14:07 UTC - End Prediction: World continues. - End of Era: Not specified. - The μ part of (+1) Testament: Linux, Python. - The λ part of (+1) Testament: Haskell, Coq, Lean, Nix. - Reverse Mathematics (1999). Stephen Simpson's Subsystems of Second Order Arithmetic. Gerald Sacks (from Reminisces of Logicians) was his advisor. - Constructive school mentioned. - Eventually we get to now. - The lambdas create Dependent Types. - The Lambdas create Nix. - Now Lambdas & Mus reuniting. - Lots of the Mus who care are lost. - The Lambdas kept our history alive. - Perfection is achieved not when there's nothing more to add, but when there's nothing left to take away.