SWI-Prolog uses standard `Edinburgh' syntax. A description of this syntax can be found in the Prolog books referenced in the introduction. Below are some non-standard or non-common constructs that are accepted by SWI-Prolog:
0'<char>
<char>
.
To test whether C is a lower case character one can use
`between(0'a, 0'z, C)
'.
/* ... /* .... */ ... */
/* ... */
comment statement can be nested. This is useful
if some code with /* ... */
comment statements in it should be
commented out.