Write a stub for the function whose declaration is given below. Do not write a program that calls this, just write the stub.

Hint: This is very short.

```
double yield (double pressure,
double density, double temp);
// Precondition: pressure is newtons per square meter
// density is in kilograms per cubic meter
// temp is in degrees Celcius
// Postcondition: Return value is the relative yield of
// a chemical process.It is a number between 0 and 1.
// 0 means no output and 1 means ideal yield.
```

```
// THIS IS JUST A STUB
double yield (double pressure,
double density, double temp);
{
return 0.25; // Not correct, but
// sufficient for testing
}
```