| Truncated tetraapeirogonal tiling | |
|---|---|
![]() Poincaré disk model of the hyperbolic plane  | |
| Type | Hyperbolic uniform tiling | 
| Vertex configuration | 4.8.∞ | 
| Schläfli symbol | tr{∞,4} or | 
| Wythoff symbol | 2 ∞ 4 | | 
| Coxeter diagram | |
| Symmetry group | [∞,4], (*∞42) | 
| Dual | Order 4-infinite kisrhombille | 
| Properties | Vertex-transitive | 
In geometry, the truncated tetraapeirogonal tiling is a semiregular tiling of the hyperbolic plane. There are one square, one octagon, and one apeirogon on each vertex. It has Schläfli symbol of tr{∞,4}.
Related polyhedra and tilings
| Paracompact uniform tilings in [∞,4] family | |||||||
|---|---|---|---|---|---|---|---|
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| {∞,4} | t{∞,4} | r{∞,4} | 2t{∞,4}=t{4,∞} | 2r{∞,4}={4,∞} | rr{∞,4} | tr{∞,4} | |
| Dual figures | |||||||
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| V∞4 | V4.∞.∞ | V(4.∞)2 | V8.8.∞ | V4∞ | V43.∞ | V4.8.∞ | |
| Alternations | |||||||
| [1+,∞,4] (*44∞)  | 
[∞+,4] (∞*2)  | 
[∞,1+,4] (*2∞2∞)  | 
[∞,4+] (4*∞)  | 
[∞,4,1+] (*∞∞2)  | 
[(∞,4,2+)] (2*2∞)  | 
[∞,4]+ (∞42)  | |
=  | 
=  | 
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| h{∞,4} | s{∞,4} | hr{∞,4} | s{4,∞} | h{4,∞} | hrr{∞,4} | s{∞,4} | |
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| Alternation duals | |||||||
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| V(∞.4)4 | V3.(3.∞)2 | V(4.∞.4)2 | V3.∞.(3.4)2 | V∞∞ | V∞.44 | V3.3.4.3.∞ | |
| *n42 symmetry mutation of omnitruncated tilings: 4.8.2n | ||||||||
|---|---|---|---|---|---|---|---|---|
| Symmetry *n42 [n,4]  | 
Spherical | Euclidean | Compact hyperbolic | Paracomp. | ||||
| *242 [2,4]  | 
*342 [3,4]  | 
*442 [4,4]  | 
*542 [5,4]  | 
*642 [6,4]  | 
*742 [7,4]  | 
*842 [8,4]...  | 
*∞42 [∞,4]  | |
| Omnitruncated figure  | 
![]() 4.8.4  | 
![]() 4.8.6  | 
![]() 4.8.8  | 
![]() 4.8.10  | 
![]() 4.8.12  | 
![]() 4.8.14  | 
![]() 4.8.16  | 
![]() 4.8.∞  | 
| Omnitruncated duals  | 
![]() V4.8.4  | 
![]() V4.8.6  | 
![]() V4.8.8  | 
![]() V4.8.10  | 
![]() V4.8.12  | 
![]() V4.8.14  | 
![]() V4.8.16  | 
![]() V4.8.∞  | 
| *nn2 symmetry mutations of omnitruncated tilings: 4.2n.2n | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Symmetry *nn2 [n,n]  | 
Spherical | Euclidean | Compact hyperbolic | Paracomp. | ||||||||||
| *222 [2,2]  | 
*332 [3,3]  | 
*442 [4,4]  | 
*552 [5,5]  | 
*662 [6,6]  | 
*772 [7,7]  | 
*882 [8,8]...  | 
*∞∞2 [∞,∞]  | |||||||
| Figure | ![]()  | 
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| Config. | 4.4.4 | 4.6.6 | 4.8.8 | 4.10.10 | 4.12.12 | 4.14.14 | 4.16.16 | 4.∞.∞ | ||||||
| Dual | ![]()  | 
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| Config. | V4.4.4 | V4.6.6 | V4.8.8 | V4.10.10 | V4.12.12 | V4.14.14 | V4.16.16 | V4.∞.∞ | ||||||
Symmetry
The dual of this tiling represents the fundamental domains of [∞,4], (*∞42) symmetry. There are 15 small index subgroups constructed from [∞,4] by mirror removal and alternation. Mirrors can be removed if its branch orders are all even, and cuts neighboring branch orders in half. Removing two mirrors leaves a half-order gyration point where the removed mirrors met. In these images fundamental domains are alternately colored black and white, and mirrors exist on the boundaries between colors. The subgroup index-8 group, [1+,∞,1+,4,1+] (∞2∞2) is the commutator subgroup of [∞,4].
A larger subgroup is constructed as [∞,4*], index 8, as [∞,4+], (4*∞) with gyration points removed, becomes (*∞∞∞∞) or (*∞4), and another [∞*,4], index ∞ as [∞+,4], (∞*2) with gyration points removed as (*2∞). And their direct subgroups [∞,4*]+, [∞*,4]+, subgroup indices 16 and ∞ respectively, can be given in orbifold notation as (∞∞∞∞) and (2∞).
| Small index subgroups of [∞,4], (*∞42) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Index | 1 | 2 | 4 | ||||||||
| Diagram | ![]()  | 
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| Coxeter | [∞,4] | 
[1+,∞,4] | 
[∞,4,1+] | 
[∞,1+,4] | 
[1+,∞,4,1+] | 
[∞+,4+] | |||||
| Orbifold | *∞42 | *∞44 | *∞∞2 | *∞222 | *∞2∞2 | ∞2× | |||||
| Semidirect subgroups | |||||||||||
| Diagram | ![]()  | 
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| Coxeter | [∞,4+] | 
[∞+,4] | 
[(∞,4,2+)] | 
[1+,∞,1+,4] =  | 
[∞,1+,4,1+] =  | ||||||
| Orbifold | 4*∞ | ∞*2 | 2*∞2 | ∞*22 | 2*∞∞ | ||||||
| Direct subgroups | |||||||||||
| Index | 2 | 4 | 8 | ||||||||
| Diagram | ![]()  | 
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| Coxeter | [∞,4]+ | 
[∞,4+]+ | 
[∞+,4]+ | 
[∞,1+,4]+ | 
[∞+,4+]+ = [1+,∞,1+,4,1+] | ||||||
| Orbifold | ∞42 | ∞44 | ∞∞2 | ∞222 | ∞2∞2 | ||||||
| Radical subgroups | |||||||||||
| Index | 8 | ∞ | 16 | ∞ | |||||||
| Diagram | ![]()  | 
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| Coxeter | [∞,4*] | 
[∞*,4] | 
[∞,4*]+ | 
[∞*,4]+ | |||||||
| Orbifold | *∞∞∞∞ | *2∞ | ∞∞∞∞ | 2∞ | |||||||
See also
References
- John H. Conway, Heidi Burgiel, Chaim Goodman-Strauss, The Symmetries of Things 2008, ISBN 978-1-56881-220-5 (Chapter 19, The Hyperbolic Archimedean Tessellations)
 - "Chapter 10: Regular honeycombs in hyperbolic space". The Beauty of Geometry: Twelve Essays. Dover Publications. 1999. ISBN 0-486-40919-8. LCCN 99035678.
 




































































