steenrod% g++ -o rat-driver-1 rat-driver-1.cc rational.o
steenrod% rat-driver-1
The following rational numbers have been defined
  z             i(4)         r(3, 5)
0 / 1          4 / 1          3 / 5
The corresponding decimal values are:
0.00000       4.00000        0.60000

Enter a fraction:  2/3
Two additional rational numbers are:
Your z       sum z + r
2 / 3         19 / 15

steenrod% rat-driver-1
The following rational numbers have been defined
  z             i(4)         r(3, 5)
0 / 1          4 / 1          3 / 5
The corresponding decimal values are:
0.00000       4.00000        0.60000

Enter a fraction:  2/0
rational.cc:43: failed assertion `denominator != 0'
IOT trap (core dumped)
steenrod% rat-driver-1
The following rational numbers have been defined
  z             i(4)         r(3, 5)
0 / 1          4 / 1          3 / 5
The corresponding decimal values are:
0.00000       4.00000        0.60000

Enter a fraction:  2   /   3
Two additional rational numbers are:
Your z       sum z + r
2 / 3         19 / 15

steenrod% rat-driver-1
The following rational numbers have been defined
  z             i(4)         r(3, 5)
0 / 1          4 / 1          3 / 5
The corresponding decimal values are:
0.00000       4.00000        0.60000

Enter a fraction:  2 * 3
rational.cc:42: failed assertion `divSign == '/''
IOT trap (core dumped)