Similar to 良設定問題

Square root of 2

Power of two

Two's complement

Bipartite graph

Three-dimensional space

Three-valued logic

Square root of 3

Four-dimensional space

Four fours

Five lemma

Five-dimensional space

Square root of 5

Square root of 6

Six-dimensional space

Square root of 7

Figure-eight knot (mathematics)

Nine lemma

One-form (differential geometry)

Partition of unity

Two-form

Twelfth root of two

Natural logarithm of 2

Ages of Three Children puzzle

4-manifold