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# Subtract operator overload

Project: Fractions

Unit: DelphiDabbler.Lib.Fractions

Record: TFraction

Applies to: ~>0.1

``````class operator Subtract(const A, B: TFraction): TFraction;
``````

## Description

This operator overload permits one TFraction to be subtracted from another using the `-` operator.

The result of the subtraction is returned as a new TFraction instance, reduced to its lowest terms.

One of the operands may be either an integer or floating point value. The Implicit operator takes care of converting the integer and floating point operands to a TFraction before performing the subtraction.

### Example

``````var
F1, F2, FRes: TFraction;
begin
F1 := TFraction.Create(2, 3);
F2 := TFraction.Create(5, 6);
FRes := F1 - F2;  // 2/3 - 5/6 = 4/6 - 5/6 = -1/6
Assert((FRes.Numerator = -1) and (FRes.Denominator = 6));
F2 := TFraction.Create(-5, 6);
FRes := 1 - F2;   // 1 - -5/6 = 6/6 - -5/6 = 11/6
Assert((FRes.Numerator = 11) and (FRes.Denominator = 6));
F1 := TFraction.Create(3, 4);
FRes := F1 - 0.25;  // 3/4 - 0.25 = 3/4 - 1/4 = 2/4 = 1/2
Assert((FRes.Numerator = 1) and (FRes.Denominator = 2));
end;
``````