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 these pages are every claim they check, collected by listening to the assertions as the drawings are made. Nothing on them 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 9189 distinct kinds of claim, tested 54691 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

117 kinds of claim · 52 placements

conic

91 kinds of claim · 38 placements

euclid

28 kinds of claim · 22 placements

figurate

29 kinds of claim · 19 placements

golden

46 kinds of claim · 15 placements

inversion

75 kinds of claim · 30 placements

iso

108 kinds of claim · 26 placements

ordinary

56 kinds of claim · 28 placements

polyhedron

81 kinds of claim · 43 placements

pythagoras

70 kinds of claim · 46 placements

reuleaux

51 kinds of claim · 25 placements

unroll

20 kinds of claim · 17 placements

voronoi

50 kinds of claim · 32 placements

Analysis

9 families

circle-to-sine

29 kinds of claim · 21 placements

converge

88 kinds of claim · 30 placements

convex

66 kinds of claim · 37 placements

exponential

33 kinds of claim · 26 placements

fourier

74 kinds of claim · 43 placements

harmonic

201 kinds of claim · 95 placements

riemann

107 kinds of claim · 62 placements

secant

37 kinds of claim · 23 placements

taylor

100 kinds of claim · 37 placements

All figures · All essays