The ledger

What the figures prove

This collection claims that a picture can be an argument rather than an illustration of one. That is a strong claim, so the generators check it while they draw — and this page is every claim they check, collected by listening to the assertions as the drawings are made. Nothing on it was typed in.

A dissection whose pieces overlap by two pixels looks exactly as convincing as one that works. A graph captioned as having an Eulerian circuit looks exactly like one that has an Eulerian circuit. The reader cannot tell, and for a long time neither could this site — a figure here carried a printed vertex degree that was simply wrong, through every gate, from the day it was written.

So the assertions are part of the drawing machinery, and the generators call them while drawing. A dissection must tile its target with no overlap, no gap and nothing outside it; congruent pieces must really be congruent; a quoted number must be computed from the drawing rather than typed beside it. A figure that does not prove its caption refuses to be drawn at all.

116 of 116 generator families reach an assertion. Between them they make 4964 distinct kinds of claim, tested 9139 times in the build that produced this page.

Every line below was collected by running each family at the parameters the essays actually use and recording what it asserted. A family that stops checking something loses its line here; a claim whose wording changes changes here with it. That is the only way this page is worth anything: a hand-written list of what code does drifts in exactly one direction, which is towards claiming more than exists.

What it does not say: that the claim is the right claim. An assertion compares a drawing against the arithmetic that produced it, and when a generator is handed an argument outside the range its picture means, both are wrong in the same way and they agree. A separate check covers that, and it still names families that would accept one.

Geometry

13 families

circle-angle

39 kinds of claim · 19 placements

conic

48 kinds of claim · 28 placements

euclid

4 kinds of claim · 11 placements

figurate

2 kinds of claim · 8 placements

golden

9 kinds of claim · 5 placements

inversion

75 kinds of claim · 30 placements

iso

25 kinds of claim · 5 placements

ordinary

14 kinds of claim · 6 placements

polyhedron

81 kinds of claim · 43 placements

pythagoras

70 kinds of claim · 46 placements

reuleaux

51 kinds of claim · 25 placements

unroll

2 kinds of claim · 7 placements

voronoi

50 kinds of claim · 32 placements

Analysis

9 families

circle-to-sine

3 kinds of claim · 8 placements

converge

17 kinds of claim · 7 placements

convex

66 kinds of claim · 37 placements

exponential

33 kinds of claim · 26 placements

fourier

38 kinds of claim · 32 placements

harmonic

68 kinds of claim · 51 placements

riemann

37 kinds of claim · 29 placements

secant

37 kinds of claim · 23 placements

taylor

48 kinds of claim · 26 placements

Algebra

8 families

algebra-tiles

14 kinds of claim · 9 placements

complex-turn

52 kinds of claim · 27 placements

eliminate

16 kinds of claim · 5 placements

group

120 kinds of claim · 36 placements

linear-map

137 kinds of claim · 89 placements

projection

70 kinds of claim · 30 placements

quaternion

109 kinds of claim · 33 placements

wiring

84 kinds of claim · 28 placements

Discrete

12 families

bipartite

17 kinds of claim · 11 placements

clock

19 kinds of claim · 19 placements

complete-graph

61 kinds of claim · 37 placements

euler-path

54 kinds of claim · 30 placements

flow

28 kinds of claim · 6 placements

genfun

15 kinds of claim · 6 placements

map-colour

26 kinds of claim · 23 placements

number-spiral

8 kinds of claim · 8 placements

pascal

32 kinds of claim · 31 placements

pigeonhole

6 kinds of claim · 11 placements

progression

23 kinds of claim · 11 placements

triangulation

51 kinds of claim · 36 placements

Topology

9 families

euler-solid

43 kinds of claim · 19 placements

fixed-point

45 kinds of claim · 25 placements

gluing

52 kinds of claim · 27 placements

knot

56 kinds of claim · 32 placements

loops

118 kinds of claim · 64 placements

mobius

16 kinds of claim · 16 placements

mobius-cut

3 kinds of claim · 4 placements

parity

66 kinds of claim · 28 placements

stereographic

34 kinds of claim · 36 placements

Probability

10 families

bayes

16 kinds of claim · 12 placements

birthday

5 kinds of claim · 7 placements

buffon

7 kinds of claim · 9 placements

chain

100 kinds of claim · 42 placements

derange

52 kinds of claim · 32 placements

galton

6 kinds of claim · 12 placements

rgraph

38 kinds of claim · 33 placements

sample

36 kinds of claim · 21 placements

spread

105 kinds of claim · 41 placements

walk

54 kinds of claim · 35 placements

Number

11 families

approx

10 kinds of claim · 5 placements

continued

35 kinds of claim · 14 placements

descent

11 kinds of claim · 7 placements

factor

28 kinds of claim · 21 placements

ferrers

37 kinds of claim · 30 placements

irrational

34 kinds of claim · 20 placements

lattice-circle

79 kinds of claim · 47 placements

mediant

45 kinds of claim · 24 placements

necklace

13 kinds of claim · 9 placements

reciprocity

45 kinds of claim · 21 placements

sieve

73 kinds of claim · 55 placements

Dynamics

11 families

attractor

32 kinds of claim · 31 placements

automaton

6 kinds of claim · 13 placements

basins

6 kinds of claim · 6 placements

bifurcation

10 kinds of claim · 13 placements

billiard

64 kinds of claim · 29 placements

boxcount

41 kinds of claim · 23 placements

circle-map

40 kinds of claim · 24 placements

cobweb

76 kinds of claim · 49 placements

collatz

44 kinds of claim · 30 placements

complex-set

11 kinds of claim · 12 placements

divergence

12 kinds of claim · 13 placements

Logic

15 families

chains

20 kinds of claim · 13 placements

connectives

8 kinds of claim · 7 placements

disc-model

14 kinds of claim · 9 placements

ef-game

67 kinds of claim · 31 placements

infinite

32 kinds of claim · 22 placements

karnaugh

12 kinds of claim · 9 placements

kripke

72 kinds of claim · 40 placements

lattice

55 kinds of claim · 42 placements

opens

15 kinds of claim · 5 placements

ordinal

45 kinds of claim · 35 placements

relation-grid

13 kinds of claim · 22 placements

syllogism

8 kinds of claim · 7 placements

tree

73 kinds of claim · 34 placements

truth-table

11 kinds of claim · 12 placements

venn

11 kinds of claim · 9 placements

Computation

11 families

check-digit

8 kinds of claim · 2 placements

construct

83 kinds of claim · 47 placements

cube-code

22 kinds of claim · 16 placements

degree

44 kinds of claim · 32 placements

dissect

58 kinds of claim · 22 placements

finite-field

16 kinds of claim · 16 placements

hamming-code

37 kinds of claim · 17 placements

incidence

26 kinds of claim · 17 placements

latin

93 kinds of claim · 30 placements

lcg

59 kinds of claim · 36 placements

poly-code

32 kinds of claim · 14 placements

Applied

7 families

apportion

101 kinds of claim · 38 placements

ballot

191 kinds of claim · 57 placements

coalition

92 kinds of claim · 41 placements

divide

53 kinds of claim · 24 placements

game

82 kinds of claim · 36 placements

match

49 kinds of claim · 25 placements

polytope

99 kinds of claim · 43 placements

The figure library · All essays