#C reads a following object, which must be a list of length two whose elements are both reals. These reals denote, respectively, the real and imaginary parts of a complex number. If the two parts as notated are not of the same data type, then they are converted according to the rules of floating-point contagion described in Section 220.127.116.11 (Contagion in Numeric Operations).
#C(real imag) is equivalent to #.(complex (quote real) (quote imag)), except that #C is not affected by *read-eval*. See the function complex.
The next figure contains examples of the use of #C.
#C(3.0s1 2.0s-1) ;A complex with small float parts. #C(5 -3) ;A ``Gaussian integer'' #C(5/3 7.0) ;Will be converted internally to #C(1.66666 7.0) #C(0 1) ;The imaginary unit; that is, i.
Figure 2-21. Complex Number Example
For further information, see Section 18.104.22.168.4 (Printing Complexes) and Section 22.214.171.124 (Syntax of a Complex).