From 2a2d8f81951d9c0426ecb04abfdb6e29e568ed49 Mon Sep 17 00:00:00 2001 From: Joshua Potter Date: Mon, 19 Feb 2024 07:05:13 -0700 Subject: [PATCH] Restructured notes on combinatorics. --- .../plugins/obsidian-to-anki-plugin/data.json | 20 ++- notes/_journal/2024-02-19.md | 11 ++ notes/_journal/{ => 2024-02}/2024-02-17.md | 0 notes/_journal/2024-02/2024-02-18.md | 23 ++++ notes/c/strings.md | 28 ++-- notes/combinatorics/additive-principle.md | 56 ++++++++ notes/combinatorics/index.md | 86 ------------- .../combinatorics/multiplicative-principle.md | 120 ++++++++++++++++++ notes/gawk/variables.md | 4 +- notes/logic/boolean-algebra.md | 16 +++ notes/logic/equiv-trans.md | 10 +- notes/posix/signals.md | 16 +++ 12 files changed, 276 insertions(+), 114 deletions(-) create mode 100644 notes/_journal/2024-02-19.md rename notes/_journal/{ => 2024-02}/2024-02-17.md (100%) create mode 100644 notes/_journal/2024-02/2024-02-18.md create mode 100644 notes/combinatorics/additive-principle.md create mode 100644 notes/combinatorics/multiplicative-principle.md diff --git a/notes/.obsidian/plugins/obsidian-to-anki-plugin/data.json b/notes/.obsidian/plugins/obsidian-to-anki-plugin/data.json index 558f34e..8dc322c 100644 --- a/notes/.obsidian/plugins/obsidian-to-anki-plugin/data.json +++ b/notes/.obsidian/plugins/obsidian-to-anki-plugin/data.json @@ -89,7 +89,7 @@ "c/escape-sequences.md": "0d6219ebb51f6f21e026de67603e25b8", "c/index.md": "a021c92f19831bdd2bca4cbf813882fe", "gawk/index.md": "dd851e023e11c556c0272a0dcb6dd55d", - "gawk/variables.md": "a7d95bd458e07b5a329c62366f368c8d", + "gawk/variables.md": "73b12bd0d7d6f97b4a7285aaf2c45bfa", "index.md": "e48e895feeed7046425bb2ee15419770", "journal/2024-01-31.md": "7c7fbfccabc316f9e676826bf8dfe970", "journal/2024-02-01.md": "3aa232387d2dc662384976fd116888eb", @@ -101,7 +101,7 @@ "nix/callPackage.md": "140a02e57cd01d646483e3c21d72243d", "nix/index.md": "4efc7fcc4ea22834ba595497e5fb715c", "posix/index.md": "97b1b8ecb9a953e855a9acf0ab25b8c8", - "posix/signals.md": "2120ddd933fc0d57abb93c33f639afd8", + "posix/signals.md": "4fe63c3c9507b2e15c9ad6f3a2b541db", "templates/daily.md": "7866014e730e85683155207a02e367d8", "posix/regexp.md": "43825a1b9ed0dd7eeb1b6fe35c928bfe", "journal/2024-02-04.md": "e2b5678fc53d7284b71ed6820c02b954", @@ -114,7 +114,7 @@ "_journal/2024-02-02.md": "a3b222daee8a50bce4cbac699efc7180", "_journal/2024-02-01.md": "3aa232387d2dc662384976fd116888eb", "_journal/2024-01-31.md": "7c7fbfccabc316f9e676826bf8dfe970", - "logic/equiv-trans.md": "afcd52fefbbbb8397220194062626a7a", + "logic/equiv-trans.md": "4d825c23bf54e8b1e645584d52b2b993", "_journal/2024-02-07.md": "8d81cd56a3b33883a7706d32e77b5889", "algorithms/loop-invariants.md": "cbefc346842c21a6cce5c5edce451eb2", "algorithms/loop-invariant.md": "d883dfc997ee28a7a1e24b995377792b", @@ -149,10 +149,10 @@ "_journal/2024-02/2024-02-11.md": "afee9f502b61e17de231cf2f824fbb32", "encoding/ascii.md": "c01e50f96d0493d94dc4d520c0b6bb71", "encoding/index.md": "071cfa6a5152efeda127b684f420d438", - "c/strings.md": "e08be6bdc820ec4903480a736448a5d7", + "c/strings.md": "2c3b6ecf6cf1815598a7be623983856c", "logic/truth-tables.md": "7892ceaa416c9a65acc79ca1e6ff778f", "logic/short-circuit.md": "26d300f407f14883022d0ef8dc4f7300", - "logic/boolean-algebra.md": "370065481448e60aa8ffa67a437b5482", + "logic/boolean-algebra.md": "f9101b2dfdedb73dc13c34c1a70a0010", "_journal/2024-02-13.md": "6242ed4fecabf95df6b45d892fee8eb0", "_journal/2024-02/2024-02-12.md": "618c0035a69b48227119379236a02f44", "binary/shifts.md": "146ee4898faa13b26f00a31024020c2e", @@ -165,10 +165,16 @@ "algebra/floor-ceiling.md": "456fa31bedb9ec7c2fa1d6f75db81dec", "algebra/index.md": "90b842eb694938d87c7c68779a5cacd1", "algorithms/binary-search.md": "08cb6dc2dfb204a665d8e8333def20ca", - "_journal/2024-02-17.md": "0fad7bf64837646e1018885504d40f41", + "_journal/2024-02-17.md": "7c37cb10515ed3d2f5388eaf02a67048", "_journal/2024-02/2024-02-16.md": "e701902e369ec53098fc2deed4ec14fd", "binary/integer-encoding.md": "a2c8c83a20f1124fd5af0f3c23894284", - "combinatorics/index.md": "c5b005bdce7ab01facfd614b00938ef2" + "combinatorics/index.md": "f9de9671fdb6068ef2bb5e63051734be", + "_journal/2024-02-18.md": "67e36dbbb2cac699d4533b5a2eaeb629", + "_journal/2024-02/2024-02-17.md": "7c37cb10515ed3d2f5388eaf02a67048", + "combinatorics/multiplicative-principle.md": "aec83fc4bafad4ae17bd3b4e92e068a1", + "combinatorics/additive-principle.md": "99320b513f16ef6be62bf766cfbd328d", + "_journal/2024-02-19.md": "77ade15d43f3fba69bde96d0e062ec13", + "_journal/2024-02/2024-02-18.md": "67e36dbbb2cac699d4533b5a2eaeb629" }, "fields_dict": { "Basic": [ diff --git a/notes/_journal/2024-02-19.md b/notes/_journal/2024-02-19.md new file mode 100644 index 0000000..00d3eae --- /dev/null +++ b/notes/_journal/2024-02-19.md @@ -0,0 +1,11 @@ +--- +title: "2024-02-19" +--- + +- [x] Anki Flashcards +- [x] KoL +- [ ] Sheet Music (10 min.) +- [ ] OGS (1 Life & Death Problem) +- [ ] Korean (Read 1 Story) +- [ ] Interview Prep (1 Practice Problem) +- [ ] Log Work Hours (Max 3 hours) \ No newline at end of file diff --git a/notes/_journal/2024-02-17.md b/notes/_journal/2024-02/2024-02-17.md similarity index 100% rename from notes/_journal/2024-02-17.md rename to notes/_journal/2024-02/2024-02-17.md diff --git a/notes/_journal/2024-02/2024-02-18.md b/notes/_journal/2024-02/2024-02-18.md new file mode 100644 index 0000000..93a722e --- /dev/null +++ b/notes/_journal/2024-02/2024-02-18.md @@ -0,0 +1,23 @@ +--- +title: "2024-02-18" +--- + +- [x] Anki Flashcards +- [x] KoL +- [ ] Sheet Music (10 min.) +- [x] OGS (1 Life & Death Problem) +- [ ] Korean (Read 1 Story) +- [ ] Interview Prep (1 Practice Problem) +- [ ] Log Work Hours (Max 3 hours) + +* 101weiqi problems (serial numbers) + * Q-59934 + * Q-264298 + * Q-349700 + * Q-138042 + * Q-11151 + * Q-267485 + * Q-84172 + * Q-87250 + * Q-260737 + * Q-12517 \ No newline at end of file diff --git a/notes/c/strings.md b/notes/c/strings.md index 9103af0..66eaed8 100644 --- a/notes/c/strings.md +++ b/notes/c/strings.md @@ -168,7 +168,7 @@ END%% %%ANKI Cloze -The {`d` and `i`} format specifer(s) output a(n) {decimal `signed int`}. +The {`d` and `i`} format specifers output a {decimal `signed int`}. Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -184,7 +184,7 @@ END%% %%ANKI Cloze -The {`u`} format specifier(s) output a(n) {decimal `unsigned int`}. +The {`u`} format specifier outputs a {decimal `unsigned int`}. Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -201,7 +201,7 @@ END%% %%ANKI Basic -Which format specifier(s) were probably used to yield `printf` output `-12`? +Which format specifiers were probably used to yield `printf` output `-12`? Back: `d` or `i` Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -219,7 +219,7 @@ END%% %%ANKI Cloze -The {`x`} format specifier(s) output a(n) {lowercase hexadecimal `unsigned int`}. +The {`x`} format specifier outputs a {lowercase hexadecimal `unsigned int`}. Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -227,7 +227,7 @@ END%% %%ANKI Basic -Which format specifier(s) were probably used to yield `printf` output `7af`? +Which format specifier were probably used to yield `printf` output `7af`? Back: `x` Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -236,7 +236,7 @@ END%% %%ANKI Cloze -The {`X`} format specifier(s) output a(n) {uppercase hexadecimal `unsigned int`}. +The {`X`} format specifier outputs an {uppercase hexadecimal `unsigned int`}. Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -244,7 +244,7 @@ END%% %%ANKI Basic -Which format specifier(s) were probably used to yield `printf` output `7AF`? +Which format specifier were probably used to yield `printf` output `7AF`? Back: `X` Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -262,7 +262,7 @@ END%% %%ANKI Cloze -The {`o`} format specifier(s) output a(n) {octal `unsigned int`}. +The {`o`} format specifier outputs an {octal `unsigned int`}. Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -279,7 +279,7 @@ END%% %%ANKI Cloze -The {`s`} format specifier(s) output a(n) {`NUL`-terminated string}. +The {`s`} format specifiers outputs a {`NUL`-terminated string}. Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -287,7 +287,7 @@ END%% %%ANKI Basic -Which format specifier(s) were probably used to yield `printf` output `abc`? +Which format specifier was probably used to yield `printf` output `abc`? Back: `s` Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -296,7 +296,7 @@ END%% %%ANKI Cloze -The {`c`} format specifier(s) output a(n) {`char` character}. +The {`c`} format specifier outputs a {`char` character}. Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -304,7 +304,7 @@ END%% %%ANKI Basic -Which format specifier(s) were probably used to yield `printf` output `a`? +Which format specifier was probably used to yield `printf` output `a`? Back: `c` Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -313,7 +313,7 @@ END%% %%ANKI Cloze -The {`p`} format specifier(s) output a(n) {`void*` address}. +The {`p`} format specifier outputs a {`void*` address}. Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf @@ -321,7 +321,7 @@ END%% %%ANKI Basic -Which format specifier(s) were probably used to yield `printf` output `0b80000000`? +Which format specifier was probably used to yield `printf` output `0b80000000`? Back: `p` Reference: “Printf,” in *Wikipedia*, January 18, 2024, [https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962](https://en.wikipedia.org/w/index.php?title=Printf&oldid=1196716962). Tags: printf diff --git a/notes/combinatorics/additive-principle.md b/notes/combinatorics/additive-principle.md new file mode 100644 index 0000000..ae46769 --- /dev/null +++ b/notes/combinatorics/additive-principle.md @@ -0,0 +1,56 @@ +--- +title: Additive Principle +TARGET DECK: Obsidian::STEM +FILE TAGS: combinatorics set +tags: + - combinatorics +--- + +## Overview + +The **additive principle** states that two finite and disjoint sets $A$ and $B$ satisfy $$|A \cup B| = |A| + |B|$$ + +%%ANKI +Basic +What does the additive principle state? +Back: Given finite and disjoint sets $A$ and $B$, $|A \cup B| = |A| + |B|$. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +The additive property applies to sets exhibiting what two properties? +Back: Finiteness and disjointedness. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +Why does $|A \cup B| \neq |A| + |B|$ in the general sense? +Back: Members of $A \cap B$ are counted twice erroneously. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +Which C construct corresponds to the additive property? +Back: `union` +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). +Tags: c + +END%% + +%%ANKI +Basic +How do we denote $A$ and $B$ are disjoint using standard set notation? +Back: $A \cap B = \varnothing$ +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +## References + +* Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). \ No newline at end of file diff --git a/notes/combinatorics/index.md b/notes/combinatorics/index.md index 0785cde..bfcb865 100644 --- a/notes/combinatorics/index.md +++ b/notes/combinatorics/index.md @@ -1,89 +1,3 @@ --- title: Combinatorics -TARGET DECK: Obsidian::STEM -FILE TAGS: combinatorics set -tags: - - combinatorics - - set --- - -## Overview - -The **additive principle** states that two finite and disjoint sets $A$ and $B$ satisfy $$|A \cup B| = |A| + |B|$$ - -The **multiplicative principle** states that two finite sets $A$ and $B$ satisfy $$|A \times B| = |A| \cdot |B|$$ - -%%ANKI -Basic -What does the additive principle state? -Back: Given finite and disjoint sets $A$ and $B$, $|A \cup B| = |A| + |B|$. -Reference: Oscar Levin, _Discrete Mathematics: An Open Introduction_, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). - -END%% - -%%ANKI -Basic -What does the multiplicative principle state? -Back: Given finite sets $A$ and $B$, $|A \times B| = |A| \cdot |B|$. -Reference: Oscar Levin, _Discrete Mathematics: An Open Introduction_, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). - -END%% - -%%ANKI -Basic -The additive property applies to sets exhibiting what two properties? -Back: Finiteness and disjointedness. -Reference: Oscar Levin, _Discrete Mathematics: An Open Introduction_, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). - -END%% - -%%ANKI -Basic -The multiplicative property applies to sets exhibiting what property? -Back: Finiteness. -Reference: Oscar Levin, _Discrete Mathematics: An Open Introduction_, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). - -END%% - -%%ANKI -Cloze -The additive principle is to {$\cup$} whereas the multiplicative principle is to {$\times$}. -Reference: Oscar Levin, _Discrete Mathematics: An Open Introduction_, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). - -END%% - -%%ANKI -Basic -If $A$ is finite, how is $A \times B$ rewritten as $|A|$ disjoint sets? -Back: Given $A = \{a_1, \ldots, a_n\}$, $(\{a_1\} \times B) \cup \cdots \cup (\{a_n\} \times B)$. -Reference: Oscar Levin, _Discrete Mathematics: An Open Introduction_, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). - -END%% - -%%ANKI -Basic -If $B$ is finite, how is $A \times B$ rewritten as $|B|$ disjoint sets? -Back: Given $B = \{b_1, \ldots, b_n\}$, $(A \times \{b_1\}) \cup \cdots \cup (A \times \{b_n\})$. -Reference: Oscar Levin, _Discrete Mathematics: An Open Introduction_, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). - -END%% - -%%ANKI -Basic -How do we denote $A$ and $B$ are disjoint using standard set notation? -Back: $A \cap B = \varnothing$ -Reference: Oscar Levin, _Discrete Mathematics: An Open Introduction_, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). - -END%% - -%%ANKI -Basic -How is the cartesian product $A \times B$ defined? -Back: $A \times B = \{\langle x, y \rangle : x \in A \land y \in B\}$ -Reference: Oscar Levin, _Discrete Mathematics: An Open Introduction_, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). - -END%% - -## References - -* Oscar Levin, _Discrete Mathematics: An Open Introduction_, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). \ No newline at end of file diff --git a/notes/combinatorics/multiplicative-principle.md b/notes/combinatorics/multiplicative-principle.md new file mode 100644 index 0000000..aea86b9 --- /dev/null +++ b/notes/combinatorics/multiplicative-principle.md @@ -0,0 +1,120 @@ +--- +title: Combinatorics +TARGET DECK: Obsidian::STEM +FILE TAGS: combinatorics set +tags: + - combinatorics + - set +--- + +## Overview + +The **multiplicative principle** states that two finite sets $A$ and $B$ satisfy $$|A \times B| = |A| \cdot |B|$$ + +%%ANKI +Basic +What does the multiplicative principle state? +Back: Given finite sets $A$ and $B$, $|A \times B| = |A| \cdot |B|$. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +The multiplicative property applies to sets exhibiting what property? +Back: Finiteness. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Cloze +{`union`} is to the additive property whereas {`struct`} is to the multiplicative property. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). +Tags: c + +END%% + +%%ANKI +Basic +Which C construct corresponds to the multiplicative property? +Back: `struct` +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). +Tags: c + +END%% + +%%ANKI +Cloze +The additive principle is to {$\cup$} whereas the multiplicative principle is to {$\times$}. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +If $A$ is finite, how is $A \times B$ rewritten as $|A|$ disjoint sets? +Back: Given $A = \{a_1, \ldots, a_n\}$, $(\{a_1\} \times B) \cup \cdots \cup (\{a_n\} \times B)$. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +If $B$ is finite, how is $A \times B$ rewritten as $|B|$ disjoint sets? +Back: Given $B = \{b_1, \ldots, b_n\}$, $(A \times \{b_1\}) \cup \cdots \cup (A \times \{b_n\})$. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +How is the cartesian product $A \times B$ defined? +Back: $A \times B = \{\langle x, y \rangle : x \in A \land y \in B\}$ +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +How many functions exist between $\{1, 2, 3, 4, 5\}$ and $\{a, b, c, d\}$? +Back: $4 \cdot 4 \cdot 4 \cdot 4 \cdot 4 = 4^5$ +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +How many functions exist between finite sets $A$ and $B$? +Back: $|B|^{|A|}$ +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +What combinatorial concept explains the number of functions between two finite sets? +Back: The multiplicative principle. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +How is the "count of three letter license plates" reimagined as a count of functions? +Back: As the number of functions from $\{1, 2, 3\}$ to $\{A, B, \ldots, Z\}$. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +%%ANKI +Basic +How is the "maximum unsigned $w$-bit number" reimagined as a count of functions? +Back: As one less than the number of functions from $\{1, 2, \ldots, w\}$ to $\{0, 1\}$. +Reference: Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). + +END%% + +## References + +* Oscar Levin, *Discrete Mathematics: An Open Introduction*, 3rd ed., n.d., [https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf](https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf). \ No newline at end of file diff --git a/notes/gawk/variables.md b/notes/gawk/variables.md index a9ba5fd..c27f9be 100644 --- a/notes/gawk/variables.md +++ b/notes/gawk/variables.md @@ -207,7 +207,7 @@ END%% %%ANKI Basic -What does incrementing `NF` do? +What two things does incrementing `NF` do? Back: Creates the field and rebuilds the record. Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf) @@ -215,7 +215,7 @@ END%% %%ANKI Basic -What does decrementing `NF` do? +What two things does decrementing `NF` do? Back: Throws away fields and rebuilds the record. Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. [https://www.gnu.org/software/gawk/manual/gawk.pdf](https://www.gnu.org/software/gawk/manual/gawk.pdf) diff --git a/notes/logic/boolean-algebra.md b/notes/logic/boolean-algebra.md index 3f30b46..8041e60 100644 --- a/notes/logic/boolean-algebra.md +++ b/notes/logic/boolean-algebra.md @@ -19,6 +19,14 @@ Reference: Gries, David. *The Science of Programming*. Texts and Monographs in END%% +%%ANKI +Basic +What set operation parallels conjunction? +Back: $\cap$ +Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981. + +END%% + %%ANKI Basic What name is given to $\lor$ operands? @@ -27,6 +35,14 @@ Reference: Gries, David. *The Science of Programming*. Texts and Monographs in END%% +%%ANKI +Basic +What set operation parallels disjunction? +Back: $\cup$ +Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981. + +END%% + %%ANKI Basic What C logical operator corresponds to $\neg$? diff --git a/notes/logic/equiv-trans.md b/notes/logic/equiv-trans.md index 2bfda76..e4f9fe2 100644 --- a/notes/logic/equiv-trans.md +++ b/notes/logic/equiv-trans.md @@ -606,7 +606,7 @@ Basic What is the role of $E$ in textual substitution $E_e^x$? Back: It is the expression in which free occurrences of $x$ are replaced. Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981. - + END%% %%ANKI @@ -614,7 +614,7 @@ Basic What is the role of $e$ role in textual substitution $E_e^x$? Back: It is the expression that is evaluated and substituted into $E$. Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981. - + END%% %%ANKI @@ -622,7 +622,7 @@ Basic What is the role of $x$ in textual substitution $E_e^x$? Back: It is the identifier matching free occurrences in $E$ that are replaced. Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981. - + END%% %%ANKI @@ -651,7 +651,7 @@ END%% %%ANKI Basic -Why might $E_e^x = E$ be an equivalence despite identifier $x$ existing in $E$? +If $x \neq e$, why might $E_e^x = E$ be an equivalence despite $x$ existing in $E$? Back: If the only occurrences of $x$ in $E$ are bound. Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981. @@ -708,7 +708,7 @@ END%% %%ANKI Basic What is the role of $\bar{e}$ role in textual substitution $E_{\bar{e}}^{\bar{x}}$? -Back: It is the expressions that are evaluated and substituted into $E$. +Back: It is the expressions that are substituted into $E$. Reference: Gries, David. *The Science of Programming*. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981. END%% diff --git a/notes/posix/signals.md b/notes/posix/signals.md index 29916c9..e9eb377 100644 --- a/notes/posix/signals.md +++ b/notes/posix/signals.md @@ -35,6 +35,21 @@ Tags: linux::cli END%% +%%ANKI +Basic +What command can we run to print POSIX signals to the terminal? +Back: `kill -l` +Reference: Cooper, Mendel. “Advanced Bash-Scripting Guide,” n.d., 916. + +END%% + +%%ANKI +Cloze +{`ascii`} is to ASCII as {`kill -l`} is to POSIX signals. +Reference: Cooper, Mendel. “Advanced Bash-Scripting Guide,” n.d., 916. + +END%% + ### SIGHUP (1) A process receives a `SIGHUP` signal when the terminal it is attached to goes away before it finishes executing. @@ -143,4 +158,5 @@ END%% ## References +* Cooper, Mendel. “Advanced Bash-Scripting Guide,” n.d., 916. * Dowling, “A List of Signals and What They Mean.”