Two quantities are said to be equal if they are, in some well-defined sense, equivalent. Equality of quantities and is written .

A symbol with three horizontal line segments () resembling the equals sign is used to denote both equality by definition (e.g., means is Defined to be equal to ) and Congruence (e.g., means 13 divided by 12 leaves a Remainder of 1--a fact known to all readers of analog clocks).

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1999-05-25