võrdusmärg

Võrdusmärk, commonly known as the equals sign, is a mathematical symbol used to indicate equality. Its appearance is two parallel horizontal lines of equal length. The symbol was invented by Welsh mathematician Robert Recorde in 1557. He chose the two parallel lines because he believed that nothing could be more equal than two parallel lines of the same length.

The võrdusmärk is fundamental to algebra and all of mathematics. It signifies that the expression on its left side has the same value or meaning as the expression on its right side. For example, in the equation 2 + 2 = 4, the võrdusmärk asserts that the sum of 2 and 2 is equivalent to the number 4.

Beyond simple numerical equality, the võrdusmärk can also represent logical equivalence or identity in different contexts. In programming languages, a variation of the võrdusmärk is often used for assignment, where it assigns a value to a variable, distinct from checking for equality. However, in its pure mathematical sense, it strictly denotes sameness. The introduction of the võrdusmärk was a significant step in the development of mathematical notation, making it easier to express and communicate mathematical ideas clearly and unambiguously.