Bjarne Stroustrup “Programming Principles and Practice Using C++” Chapter 4 Drill 5
Using std_lib_facilities.h by Bjarne Stroustrup.

// Philipp Siedler
// Bjarne Stroustrup's PP
// Chapter 4 Drill 5
#include "std_lib_facilities.h"
int main()
{
cout << "type in two doubles or a '|' to terminate the program:\n";
double x1;
double x2;
double difference;
while (cin >> x1 >> x2)
{
if (x1 < x2){
cout << "the smaller number is x1: " << x1 << "\n";
cout << "the larger number is x2: " << x2 << "\n";
difference = x2 - x1;
if (difference <= 1.0 / 100){
cout << "the numbers are almost equal" << "\n";
}
}
else if (x1 == x2){
cout << "the numbers are equal" << "\n";
}
else{
cout << "the larger number is x1: " << x1 << "\n";
cout << "the smaller number is x2: " << x2 << "\n";
difference = x1 - x2;
if (difference <= 1.0 / 100){
cout << "the numbers are almost equal" << "\n";
}
}
}
return 0;
}

Output 1:
type in two doubles or a '|' to terminate the program:
3.001 3.002
the smaller number is x1: 3.001
the larger number is x2: 3.002
the numbers are almost equal