Worlds of David Darling
Encyclopedia of Science
   
Home > Encyclopedia of Science

cap




The symbol cap used to denote the intersection between two sets. Thus the intersection between sets P and Q is written as P cap Q. This is illustrated in a Venn diagram as the region of overlap between two sets.

The cap was first used as the symbol for intersection by Guiseppe Peano in Calcolo Geometrico secondo l'Ausdehnungslehre di H. Grassmann (1888). See also union.


Related categories

   • SETS AND SET THEORY
   • SYMBOLS AND NOTATION