Linker error: Multiple definition of...

[yshicht]

I'm having difficulties understanding the following linker error:

g++ -g -Wall mycompmain.C complex.C complex.H  -o comp
/tmp/ccQ5RLlr.o(.text+0x110): In function `operator+(double const&, Complex const&)':
/u1/004/syshicht/hw5/complex.H:30: multiple definition of `operator+(double const&, Complex const&)'
/tmp/cc42XlFh.o(.text+0x110):/u1/004/syshicht/hw5/complex.H:30: first defined here
/tmp/ccQ5RLlr.o(.text+0x13e): In function `operator-(double const&, Complex const&)':
/u1/004/syshicht/hw5/complex.H:34: multiple definition of `operator-(double const&, Complex const&)'
/tmp/cc42XlFh.o(.text+0x13e):/u1/004/syshicht/hw5/complex.H:34: first defined here
/tmp/ccQ5RLlr.o(.text+0x1ac): In function `operator*(double const&, Complex const&)':
/u1/004/syshicht/hw5/complex.H:38: multiple definition of `operator*(double const&, Complex const&)'
/tmp/cc42XlFh.o(.text+0x1ac):/u1/004/syshicht/hw5/complex.H:38: first defined here
collect2: ld returned 1 exit status
make: *** [comp] Error 1

These operators are defined in the following file:

#ifndef _COMPLEX
#define _COMPLEX

#include <iostream>
using namespace std;

class Complex {
private:
	double r, i;
public:
	Complex(const double& a = 0, const double& b = 0);
	Complex(const Complex& complexNum);
	Complex operator+(const Complex& complexNum) const;
	Complex operator-(const Complex& complexNum) const;
	Complex operator*(const Complex& complexNum) const;
	Complex operator+(const double& num) const;
	Complex operator-(const double& num) const;
	Complex operator*(const double& num) const;
	Complex& operator+=(const Complex& complexNum);
	Complex& operator-=(const Complex& complexNum);
	Complex& operator*=(const Complex& complexNum);
	Complex& operator+=(const double& num);
	Complex& operator-=(const double& num);
	Complex& operator*=(const double& num);
	bool operator==(const Complex& complexNum) const;
	bool operator!=(const Complex& complexNum) const;
	friend ostream& operator<<(ostream& stream, const Complex& complexNum);
};

Complex operator+(const double& lhs, const Complex& rhs) {
	return rhs + lhs;
}

Complex operator-(const double& lhs, const Complex& rhs) {
	return Complex(-1) * rhs + lhs;
}

Complex operator*(const double& lhs, const Complex& rhs) {
	return rhs * lhs;
}

#endif

The complex.C file doesn't have any of these operators. It only implements the member operators.
What am I doing wrong that causes these errors?
Thanks.