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:
“When it is evening, you say, It will be fair weather, for the sky is red.’ And in the morning, It will be stormy today, for the sky is red and threatening.’ You know how to interpret the appearance of the sky, but you cannot interpret the signs of the times.”
—Bible: New Testament, Matthew 16:2,3.
“I do not deny that there may be other well-founded causes for the hatred which various classes feel toward politicians, but the main one seems to me that politicians are symbols of the fact that every class must take every other class into account.”
—José Ortega Y Gasset (1883–1955)