Another Graphic Solution of Differential Equation of the Second Order

Car Rally

Construct a Counterexample to Sorites

Decomposition on Double Triacontahedron

Equivalential Formula

Expanding Ball of 30 Octahedra

Folding Schwarz's Polyhedron

Four Sign Changes

Total Variation of Function

Function Identification Game

Graph of Relation under Coordinate Transformation

Graphic Solution of a Differential Equation of the First Order

Graphic Solution of Differential Equation of the Second Order

Gyroelongated Square Dipyramid to Tetrahedron Net Dissection

Icosahedral Rotational Symmetry Types

Lukasiewicz's Three-Valued Modal Logic

Mass Center of a Truncated Cylinder

Measure of Asymmetry of Strongly Binary Trees

Net for Schwarz's Polyhedron

Nomogram of x/a+y/b

Nonograms From Mathematica Characters

Nonograms From Pixelization of a Font

Octahedral Rotational Symmetry Types

Octahedron Tessellation

Polyhedral Maps

Replacing Rhombohedra in Hexecontahedron

Signed Area of Parallelogram or Triangle Test

Solvable Nonograms

Steinitz's lemma

Surface of a Cube to Surface of Tetrahedron Dissection

Surface of Octahedron to Surface of Terahedron Dissection

Completeness Theorem of Equivalential Calculus

The Completeness Theorem of Equivalential Calculus

Total Variation of Function

Twist-Hinged Dissection of Hexagram to Two Hexagons

Two-Cube Calendar

Two Views Maze

Some Unistable Polyhedra

Vernier Caliper of Precision 0.05 mm

*Izidor Hafner, January 2014*