A graph is planar if and only if it does not contain a subdivision of either the complete graph K5 or of the bipartite graph K3,3 as a subgraph.
K5
K3,3
- Lebesgue, Henri (1875–1941)
- Lebesgue, Henri Léon
- Lebesgue integration
- Leblanc, Nicolas (1742–1806)
- Leblanc process
- Lebrun, Albert (1871–1950)
- LEC
- Le Cam Lecturer
- Le Cam, Lucien Marie (1924–2000)
- Le Chatelier, Henri Louis
- Le Chatelier, Henry Louis (1850–1936)
- lechatelierite
- Le Chatelier’s principle
- Lechfeld, Battle of (955)
- lecithin
- Leclanché cell
- Leclanché, Georges
- Lecoq de Boisbaudran, Paul-Emile
- LECP
- lect
- lectin
- lectostratotype
- lectotype
- LED
- Leda