Pedagoguery Software Inc. T-Shirts PSi logo frieze
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We currently offer four T-shirts for secure online purchasing. When ordering, please specify the size and design of each shirt (using the vendor comment box if ordering online). One T-shirt costs US$20, including shipping and handling. Buy two T-shirts at the same time for US$30, including shipping and handling. All of the T-shirts are “Fruit of the Loom” 100% heavy-weight cotton. Six sizes are available: S, M, L, XL, XXL, and XXXL.
Mask T-shirt Mask

Black ink on a white shirt.

The Mask T-shirt displays the GrafEq mascot along with its defining relation.

Click on the T-shirt icon to see a photograph.

Poly T-Shirt


Light gray ink on a black shirt.

The Poly T-shirt displays a pentagonal cupola, a truncated dodecahedron, and a hexagonal anti-prism; each in three different ways: as a three-dimensional polyhedra, as a two-dimensional net, and as a topological (Schlegel) diagram.

Strands T-Shirt


Black ink on a white shirt.

The Strands T-shirt displays fine, whispy strands along with its defining multi-equation.

Tube T-Shirt


Black ink on a white shirt.

The Tube T-shirt displays what appears to be a three-dimensional tube. Close scrutiny of the defining relation reveals that the relation is only two-dimensional and actually describes many small discs arranged so as to give the appearance of a three-dimensional tube.

T-Shirt Availability

Mask available available available   available available
Poly         available  
Strands available available available available available available
Tube available       available available
Dig Trig sold out