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### Ln

#### Synopsis

         function Ln (x: Real): Real;

or

         function Ln (z: Complex): Complex;

#### Description

The natural logarith `Ln` is the logarithm with base e, where e is the Euler number e = Exp (1) = 2.718281828...

#### Conforming to

The function `Ln` is defined in ISO 7185 Pascal; its application to complex values is defined in ISO 10206 Extended Pascal.

#### Example

         program LnDemo;
         var
           z: Complex;
         begin
           z := Cmplx (1, 1);
           z := Ln (z)  { yields Ln (SqRt (2)) + i * Pi / 4 }
                        { since Ln (i * x) = Ln Abs (x) + i * Arg (x) }
         end.

#### See also