Give aup a bool: true and false, and conditions that take one

A condition was any number, non-zero being true: done was a number field,
a view showed 1 for true, and done + 1 was no type error. Now bool is its
own type (Pure 016, module format v6):

- true and false; comparisons, text comparisons, has and ! && || give a
  bool. Bools are equal or not; they are no numbers and have no order.
- if, conditional expressions, require, where (folds, walks, filtered
  tables) take a bool. Given a number, the diagnostic says how to make
  one: "if takes a bool, not a number: compare it, as in n != 0".
- Bool states (state on = false), record fields (done = false), message,
  output and argument fields (ok: bool), lets, views and columns.
  Interpolation writes true or false. A list is not keyed by a bool.
- The examples' flags are bools (charge's holding, toggle's visible,
  tasks' done).

Checks: 20 bool diagnostics, a form using bools everywhere, an app whose
every output shows true and false (states, items, views, columns, text)
and whose replacement turns a number into a bool and back. Models hold
bools and compare them strictly: Python's True == 1 no longer hides a 1
where a true belongs. Generated programs are typed, numbers and bools.

1 files changed, 1 insertions, 1 deletions

diff --git a/README.md b/README.md
index 51a7fa1..26d1fcd 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ aup는 [Pure](/srv/git/pure.git) 런타임을 위한 **언어와 툴체인**이�
 | [Vega](/srv/git/vega.git) | aup와 Pure 위의 인터페이스 구현자(TUI·CLI·GUI·NUI) |
 
 상태: v0a(scalar 상태·키 입력·원자적 이벤트·보기), v0b(바이트·영속 문서·메시지·응답·text·커서),
-v0c(레코드·리스트·`index of`·조건식·표 보기·`fn`·`use` 라이브러리·집계·키 있는 리스트·text 비교) 동작. 그 위의 첫 인터페이스는 [Vega](/srv/git/vega.git)(`use vega`, 목록·표·톤을 TUI·CLI·문장으로).
+v0c(레코드·리스트·`index of`·조건식·표 보기·`fn`·`use` 라이브러리·집계·키 있는 리스트·text 비교·`bool`) 동작. 그 위의 첫 인터페이스는 [Vega](/srv/git/vega.git)(`use vega`, 목록·표·톤을 TUI·CLI·문장으로).
 [언어 v0](docs/design/001-language-v0.md).
 
 ```sh