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 14020 distinct kinds of claim, tested 414691 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

239 kinds of claim · 119 placements

conic

98 kinds of claim · 44 placements

euclid

69 kinds of claim · 47 placements

figurate

46 kinds of claim · 35 placements

golden

61 kinds of claim · 26 placements

inversion

75 kinds of claim · 30 placements

iso

139 kinds of claim · 50 placements

ordinary

66 kinds of claim · 46 placements

polyhedron

133 kinds of claim · 74 placements

pythagoras

86 kinds of claim · 58 placements

reuleaux

51 kinds of claim · 25 placements

unroll

68 kinds of claim · 39 placements

voronoi

76 kinds of claim · 50 placements

Analysis

9 families

circle-to-sine

78 kinds of claim · 49 placements

converge

119 kinds of claim · 46 placements

convex

77 kinds of claim · 43 placements

exponential

33 kinds of claim · 26 placements

fourier

87 kinds of claim · 55 placements

harmonic

285 kinds of claim · 155 placements

riemann

188 kinds of claim · 108 placements

secant

80 kinds of claim · 46 placements

taylor

161 kinds of claim · 60 placements

All figures · All essays