+ package:base-prelude

Append two lists, i.e.,
[x1, ..., xm] ++ [y1, ..., yn] == [x1, ..., xm, y1, ..., yn]
[x1, ..., xm] ++ [y1, ...] == [x1, ..., xm, y1, ...]
If the first list is not finite, the result is the first list.
Split the input between the two argument arrows, retagging and merging their outputs. Note that this is in general not a functor. The default definition may be overridden with a more efficient version if desired.
forms a complex number from its real and imaginary rectangular components.
An associative operation with identity zeroArrow.