digit/number: imaginary i; square root of -1.

Acts as a number punctuation mark (separating the real and the imaginary parts of a complex number); for example "ci ka'o re" means 3 + 2i. See also: kau'o, ka'o'ai, ka'o'ei.

- lujna'u
- x
_{1}is a complex number. - tolxarna'u
- x
_{1}is a real number. - kai'o
- quaternion i
- ka'o'ai
- imaginary i (non-comma)
- ka'o'ei
- imaginary i, comma - spherical coordinates: first coordinate gives magnitude (complex modulus/radius) of the number, the second number gives the angle from the positive real axis measured counterclockwise toward the 'positive' imaginary axis (default: in the primary branch/Arg) as measured in some units (which that number should contain; the contextless default will suppose radians); the angle is not normalized.
- kau'o
- generic algebra unit e
_{n} - kei'o
- quaternion j
- koi'o
- quaternion k
- ka'o zei namcu
- x
_{1}is a complex number (understood as such). - ka'ozeino zei namcu
- x
_{1}is a pure real number (such that its imaginary part is 0) understood as an example of a complex number. - nozeika'o zei namcu
- x
_{1}is a pure imaginary number (such that its real part is 0) understood as an example of a complex number.