==== ΔLIST ====
<callout type="primary" color="" icon="fa fa-book" title="Synopsis">
----
Return first differences of elements of a list
</callout>

<callout color="green" icon="fa fa-indent" title="Stack Diagram">
----
^  __Input Stack__  ^  ^  __Output Stack__  ^
|  **L<sub>data</sub>**  |  **→**  |  **L<sub>diff</sub>**  |
|  //Level 1//  |  //→//  |  //Level 1//  |

{{page>manual:chapter6:aux:legend&nofooter&noeditbtn&inline}}

| **Keyword type**  | [[manual:chapter5:basics#commands|Command]]  ||
| **Parallel list processing capabilities**  | [[manual:chapter5:listproc#group-2commands-that-must-use-dolist-to-parallel-process|Group 2]]  | //Commands that must use //''[[manual:chapter6:lists:cmd_cmddolist|DOLIST]]''// to parallel process//  |
| **Affected by flags**  | //None//  ||














</callout>

<callout color="orangered" icon="fa fa-comment" title="Description">
----
The ''ΔLIST'' command returns the first differences of the elements in the list **L<sub>data</sub>**, i.e.:
$$ data_2-data_1 \\
data_3-data_2 \\
data_4-data_3 \\
\ldots $$
The list must contain at least two elements, and the elements themselves must be suitable for mutual subtraction.
</callout>

<callout type="success" icon="true" title="Compatibility">
----
''ΔLIST'' is fully equivalent to its **userRPL** counterpart.
</callout>

<callout type="info" icon="true" title="Usage">
----
**__Input__**
<code>
4:                                      
3:                                      
2:                                      
1:                  { 39 18 5 '2*X' 73 }
…………………………………………………………………………………………………………
ΔLIST                                   
</code>
\\
**__Output__**
<code>
4:                                      
3:                                      
2:                                      
1:          { -21 -13 '2*X-5' '73-2*X' }
…………………………………………………………………………………………………………
                                        
</code>
</callout>

<callout color="darkgray" icon="fa fa-hand-o-right" title="Related Commands">
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{{page>manual:chapter6:lists&nofooter&noeditbtn&inline}}
</callout>