Von Neumann universal constructor
Comparison of implementations
As defined by von Neumann, universal construction entails the construction of passive configurations, only. As such, the concept of universal construction constituted nothing more than a literary (or, in this case, mathematical) device.

Von Neumann universal constructor

Section Title: Comparison of implementations
Table Section Text: As defined by von Neumann, universal construction entails the construction of passive configurations, only. As such, the concept of universal construction constituted nothing more than a literary (or, in this case, mathematical) device.

implementation	source	ruleset	rectangular area	number of cells	length of tape	ratio	timesteps for replication	tape code compression	tape code length	tape code type	replication mechanism	replication type	growth rate

Nobili-Pesavento, 1995	Nobili 32-state	97 × 170	6,329	145,315	22.96	6.34 × 1010	none	5 bits	binary	holistic constructor	non-repeatable	linear

Nobili, 2007	SR_CCN_AP.EVN	Nobili 32-state	97 × 100	5,313	56,325	10.60	9.59 × 109	run-length limited encoding	5 bits	binary	holistic constructor	repeatable	super-linear

Buckley, 2008	codon5.rle	Nobili 32-state	112 × 50	3,343	44,155	13.21	5.87 x 109	auto-retraction	5 bits	binary	holistic constructor	repeatable	linear

Buckley, 2008	replicator.mc	von Neumann 29-state	312 × 132	18,589	294,844	15.86	2.61 × 1011	auto-retraction	5 bits	binary	holistic constructor	repeatable	linear

Buckley, 2008	codon4.rle	Nobili 32-state	109 × 59	3,574	37,780	10.57	4.31 x 109	auto-retraction/bit generation	4 bits	binary	holistic constructor	repeatable	linear

Buckley, 2009	codon3.rle	Nobili 32-state	116 × 95	4,855	23,577	4.86	1.63 x 109	auto-retraction/bit generation/code overlay	3 bits	binary	holistic constructor	repeatable	super-linear

Buckley, 2009	PartialReplicator.mc	von Neumann 29-state	2063 × 377	264,321	NA	≈1.12 x 1014	none	4 bits	binary	partial constructor	repeatable	linear

Goucher & Buckley, 2012	phi9.rle	Nobili 32-state	122 × 60	3957	8920	2.25	auto-retraction/bit generation/code overlay/run length limited	3+ bits	ternary	holistic constructor	repeatable	super-linear

Sentence(s)

Nobili-Pesavento 32-state implementation requires 6,329 cells, a rectangle of size 97x170 and a tape that is 145,315 long.

final_sentence: Nobili-Pesavento 32-state implementation requires 6,329 cells, a rectangle of size 97x170 and a tape that is 145,315 long.