NKS code: btrees-2.eps


Backward CA evolution

In[]:=
RulePlot[CellularAutomaton[30]]
Out[]=
In[]:=
BackwardCA[rn_Integer]:=ReverseSort[Flatten[Normal/@(Merge[#,Union[Flatten[#]]&]&/@GatherBy[(Take[CellularAutomaton[rn][#],{2,4}]->#[[3]])&/@Tuples[{1,0},5],First])]]
In[]:=
BackwardCA[30]
Out[]=
{{1,1,1}{0,1},{1,1,0}{0,1},{1,0,1}{0,1},{1,0,0}{0,1},{0,1,1}{0,1},{0,1,0}{0,1},{0,0,1}{0,1},{0,0,0}{0,1}}
In[]:=
BackwardCA[90]
Out[]=
{{1,1,1}{0,1},{1,1,0}{0,1},{1,0,1}{0,1},{1,0,0}{0,1},{0,1,1}{0,1},{0,1,0}{0,1},{0,0,1}{0,1},{0,0,0}{0,1}}
In[]:=
BackwardCA[254]
Out[]=
{{1,1,1}{0,1},{1,1,0}{0},{1,0,1}{0},{1,0,0}{0},{0,1,1}{0},{0,0,1}{0},{0,0,0}{0}}
In[]:=
BackwardCA[73]
Out[]=
{{1,1,1}{0},{1,1,0}{0,1},{1,0,1}{0,1},{1,0,0}{0,1},{0,1,1}{0,1},{0,1,0}{0,1},{0,0,1}{0,1},{0,0,0}{0,1}}