Noun
1. a group of symbols that make a mathematical statement
2. directions for making something
3. a conventionalized statement expressing some fundamental principle
4. a representation of a substance using symbols for its constituent elements
5. something regarded as a normative example;
"the convention of not naming the main character""violence is the rule not the exception""his formula for impressing visitors"6. a liquid food for infants
7. (mathematics) a standard procedure for solving a class of mathematical problems;
"he determined the upper bound with Descartes' rule of signs""he gave us a general formula for attacking polynomials"