Miscellaneous Signs and Symbols
| Sign | Example | Meaning and verbal equivalent | Remarks |
|---|---|---|---|
| ≝ |
a ≝ b | a is by definition equal to b | := is also used |
| = | a = b | a equals b | ≡ may be used to emphasize that a particular equality is an identity. |
| ≠ | a ≠ b | a is not equal to b | may be used to emphasize that a is not identically equal to b. |
| ≙ | a ≙ b | a corresponds to b | On a 1:106 map: 1 cm ≙ 10 km. |
| ≈ | a ≈ b | a is approximately equal to b | The symbol ≃ is reserved for "is asymptotically equal to". |
| ∼ ∝ |
a ∼ b a ∝ b |
a is proportional to b | |
| < | a < b | a is less than b | |
| > | a > b | a is greater than b | |
| ≤ | a ≤ b | a is less than or equal to b | The symbol ≦ is also used. |
| ≥ | a ≥ b | a is greater than or equal to b | The symbol ≧ is also used. |
| ≪ | a ≪ b | a is much less than b | |
| ≫ | a ≫ b | a is much greater than b | |
| ∞ | infinity | ||
{} |
(a+b)c c {a+b}c a+bc |
ac+bc, parentheses ac+bc, square brackets ac+bc, braces ac+bc, angle brackets |
In ordinary algebra, the sequence of, {}, in order of nesting is not standardized. Special uses are made of, {}, in particular fields. |
| ∥ | AB ∥ CD | the line AB is parallel to the line CD | |
| ABCD | the line AB is perpendicular to the line CD |
Read more about this topic: ISO 31-11
Famous quotes containing the words signs and/or symbols:
“A strong nation, like a strong person, can afford to be gentle, firm, thoughtful, and restrained. It can afford to extend a helping hand to others. It’s a weak nation, like a weak person, that must behave with bluster and boasting and rashness and other signs of insecurity.”
—Jimmy Carter (James Earl Carter, Jr.)
“Children became an obsessive theme in Victorian culture at the same time that they were being exploited as never before. As the horrors of life multiplied for some children, the image of childhood was increasingly exalted. Children became the last symbols of purity in a world which was seen as increasingly ugly.”
—C. John Sommerville (20th century)