A FSMLabs whitepaper. [gview file=”https://www.yodaiken.com/wp-content/uploads/2018/05/financeandbeyond.pdf”]
Trees in informal methods
What’s a tree? First define a sequence or length n> 0 as a total map s: {1,.. n}→ X. Let Nil be the empty sequence. If s is a sequence of length n, and x is an element, then u
Linked lists
What’s a linked list? Let V be a set of values and A be a set of “addresses”. Say a map f is a “linked list element” compatible with values V and addresses A if and only if f(value)∈ V
New and or notable.
My new favorite line: “My good sir, I worry that your groundbreaking treatise will go overlooked here on Twitter” This is a great essay on programming: Operant Conditioning by Software Bugs. This is a good point on mathematics versus the
Xor patterns
The xor i mod 128 “multiplication table” as presented by Mathematica. Here is the mod 64 matrix.
More UB madness from LLVM/Clang
Via @johnregehr this further tale of compiler “optimizations” that break correct C code without even a warning by deleting a necessary null pointer check. In this example, Bar contains a stack of Foos. Sometimes the Foo stack is empty, so
informal methods applied to networks and timeouts
Distributed computation involves many interesting issues concerning shared data. Here I want to sketch out what networks look like using applied (informal) mathematics so we can look at some algorithms for consensus and data consistency. No formal methods or category
Current reading: meltdown and spectre edition
Google project zero and then The two attacks. and remediation for Spectre in LLVM. Test code. (via Lobste.rs) Limits of ASLR. Spanner,True Time and CAP See also Synchronous Processors. and processor architecture. Some papers by Stephen Kell (also via lobste.rs
Types considered harmful. From a remark by Wolfram.
Originally Nov 30, 2017. (revised 2021,2023) Russell introduced what is often viewed as his most original contribution to mathematical logic: his theory of types—which in essence tries to distinguish between sets, sets of sets, etc. by considering them to be
Current reading August 2017
Two-way string matching And an implementation in Musl. The C standard post C11 The Rube-Goldberg approach to fault tolerance in NTPd which is not worse than PTP fault tolerance but a lot worse than what is done in TimeKeeper. Interesting but