The French Encyclopædia Universalis defines it as the branch which "treats the properties of an object that are invariant if it is deformed in any continuous way, without tearing".
Encyclopædia Britannica | Encyclopædia Britannica Eleventh Edition | Europa Universalis | ''The New International Encyclopædia'' | The Encyclopædia of Ball Juggling | The Art of Heraldry: An Encyclopædia of Armory | Encyclopædia Universalis | Encyclopædia Perthensis | ''Encyclopædia Britannica'' | Edinburgh Encyclopædia | Charlie Dancey's Encyclopædia of Ball Juggling |