ka'o'ai PA5 experimental cmavo

imaginary i (non-comma)

This is literally a unit, a pure number that is treated as a scalar; it is what happens when considering C to be a field over C - ordered pairs/tuples for coordinates no longer make much sense. Thus, this number operates exactly as one might think i would/should operate: as a single number, without components. In certain bases, it can be used a pure digit (which simplifies some potential numeric strings, compared to the usage of ka'o therein). See also: ka'o (and its commentary on Jbovlaste for the justification for this word), fai'u.

In notes:

digit/number: imaginary i; square root of -1.
ka'o zei namcu
x1 is a complex number (understood as such).