There are four syntactic forms for atoms.
_" and alphanumeric characters.
`". This form of atom is used when the sequence of characters without the back-quote has been used as the name of a relation, function or action. Such a name cannot be used as an atom unless preceded by a backquote.
'" (single quote). Single quote can be included in the sequence by writing the quote twice. "
\" indicates an escape sequence, where the escape characters are case insensitive. The possible escape characters are:
|Meaning: Same as |
|Meaning: Control character.|
|Meaning: A two digit octal number.|
|Meaning: Alarm (|
|Meaning: Backspace (|
|Meaning: Delete (|
|Meaning: Escape (|
|Meaning: Formfeed (|
|Meaning: Newline (|
|Meaning: A two digits octal number.|
|Meaning: Return (|
|Meaning: Space (|
|Meaning: Horizontal tab (|
|Meaning: Vertical tab (|
|Meaning: A two digit hexadecimal number.|
Here are a few examples of quoted atoms.
'hi!' 'they''re' '\n'