function Exp (x: Real): Real;
or
function Exp (z: Complex): Complex;
The exponential function Exp computes the value of e to the power of x, where the Euler number e = Exp (1) is the base of the natural logarithm.
The function Exp is defined in ISO 7185 Pascal; its application to complex values is defined in ISO 10206 Extended Pascal.
program ExpDemo; var z: Complex; begin z := Cmplx (1, - 2 * Pi); { z = 1 - 2 pi i } z := Exp (z); { yields e = Exp (1), since Exp ix = Cos x + i Sin x } WriteLn (Ln (Re (z)) : 0 : 5) { prints 1 = Ln (Exp (1)) } end.