Concatenate two lists or a list and an element : concat augment

concat (or augment) takes as argument a list and an element or two lists.
concat (or augment) concats this list and this element, or concats these two lists.
Input :

concat([3,4,2],[1,2,4])

Or :

augment([3,4,2],[1,2,4])

Output :

[3,4,2,1,2,4]

Input :

concat([3,4,2],5)

Or :

augment([3,4,2],5)

Output :

[3,4,2,5]

Warning If you input :

concat([[3,4,2]],[[1,2,4]]

or

augment([[3,4,2]],[[1,2,4]]

the output will be:

[[3,4,2,1,2,4]]