A Calculus of Number Based on Spatial Forms - University of ...
A Calculus of Number Based on Spatial Forms - University of ...
A Calculus of Number Based on Spatial Forms - University of ...
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10<br />
Table 2.1: Deniti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> Spencer-Brown <str<strong>on</strong>g>Number</str<strong>on</strong>g>s.<br />
<str<strong>on</strong>g>Number</str<strong>on</strong>g>s<br />
0 !<br />
1 !<br />
2 !<br />
3 !<br />
Operators<br />
a + b ! ab<br />
ab! a b<br />
a b ! b :a<br />
Rules<br />
at bt :::<br />
:<br />
=<br />
:<br />
= a b ::: t<br />
a = a<br />
:a =<br />
With space as additi<strong>on</strong>, the natural numbers are easily formed. The void acts<br />
as zero and counting proceeds by accumulating marks: , , , ::: and<br />
so <strong>on</strong>. <str<strong>on</strong>g>Number</str<strong>on</strong>g>s are added by spatial collecti<strong>on</strong> whereas multiplicati<strong>on</strong> and power<br />
operati<strong>on</strong>s are composed using marks. Spencer-Brown's numbers are summarized in<br />
Table 2.1.<br />
He gives two axioms for calculating <strong>on</strong> these forms, universe and transfer. With<br />
these axioms he derives many theorems, including reexi<strong>on</strong> and null power. Universe<br />
and null power are his numerical versi<strong>on</strong>s <str<strong>on</strong>g>of</str<strong>on</strong>g> calling and crossing.<br />
Universe<br />
Transfer at bt :::<br />
Reexi<strong>on</strong> a = a<br />
Null Power :a =<br />
:<br />
=<br />
:<br />
= a b ::: t<br />
In additi<strong>on</strong> to the mark, he uses a vaguely dened col<strong>on</strong> to disambiguate c<strong>on</strong>icting<br />
results whichwould equate 0 1 ! : and 2 ! . This col<strong>on</strong> does not completely<br />
resolve the problems it was introduced for.<br />
These numbers add by spatial collecti<strong>on</strong>. For example, 3 + 2 = 5.<br />
3+2 Given<br />
+ <str<strong>on</strong>g>Number</str<strong>on</strong>g> Rewrite<br />
Additi<strong>on</strong> Rewrite<br />
5 <str<strong>on</strong>g>Number</str<strong>on</strong>g> Rewrite<br />
<str<strong>on</strong>g>Number</str<strong>on</strong>g>s multiply by the form ab ! a b . The form reduces by transfer, which<br />
distributes the whole <str<strong>on</strong>g>of</str<strong>on</strong>g> <strong>on</strong>e number throughout the units <str<strong>on</strong>g>of</str<strong>on</strong>g> the other. For example,<br />
3 2=6.