From bf127e9512b621329a345fa32bbbe3073ff1ce04 Mon Sep 17 00:00:00 2001 From: Marshall Lochbaum Date: Fri, 17 Jul 2020 23:47:49 -0400 Subject: Fix link --- problems.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'problems.md') diff --git a/problems.md b/problems.md index 3722b4b9..c5ed3246 100644 --- a/problems.md +++ b/problems.md @@ -99,7 +99,7 @@ You have to scan for headers or double-struck names (and so does a compiler). A This is a natural array operation to do, and results in an array with a joinable structure, but as Prefixes and Suffixes are monadic there's no way to specify the number of axes to use. ### And/Or/Max/Min are all tangled up -Boolean And (`∧`) and Or (`∨`) are identical to Min (`⌊`) and Max (`⌈`) when restricted to Boolean arguments, and this would fit nicely with their monadic role as sorting functions: for example `a∧b ←→ ⊑∧a‿b`. Furthermore the pairing of Min with Floor and Max with Ceiling is mnemonic only and not especially natural. The reason I have not used these glyphs for Min and Max, and have instead extended them to the somewhat superfluous [arithmetic logical functions](doc/logical.md) is that Min and Max have different [identity elements](https://aplwiki.com/wiki/Identity_element) of `∞` and `¯∞` rather than `1` and `0`. Having to code around empty arrays when using `∧´` would be a fairly big issue. +Boolean And (`∧`) and Or (`∨`) are identical to Min (`⌊`) and Max (`⌈`) when restricted to Boolean arguments, and this would fit nicely with their monadic role as sorting functions: for example `a∧b ←→ ⊑∧a‿b`. Furthermore the pairing of Min with Floor and Max with Ceiling is mnemonic only and not especially natural. The reason I have not used these glyphs for Min and Max, and have instead extended them to the somewhat superfluous [arithmetic logical functions](doc/logic.md) is that Min and Max have different [identity elements](https://aplwiki.com/wiki/Identity_element) of `∞` and `¯∞` rather than `1` and `0`. Having to code around empty arrays when using `∧´` would be a fairly big issue. The other drawback of Min (`∧`) and Max (`∨`) is that the symbols are counterintuitive, but I have found a way to remember them: consider the graph of variables `a←x` and `b←¬x` for x from 0 to 1: two crossed lines. Now the graph of `a∧b` is a caret shape and `a∨b` is a vee. -- cgit v1.2.3