Adjust to the moving target called the C++ standard. Apparently nowadays it's not allowed to define an explicit copy constructor but not an assignment operator. Consequently, defining the explicit copy constructor in terms of the implicit/automatic assignment operator for general convenience no longer works. Add assignment operators. Caution: not tested with the IBM compiler, but there's no particular reason it shouldn't work.

  /* test.ffc  - test file for ffcalc.syn grammar */

  (156.7-8.2+1.5)/3 - 7*7     /*  1  */

F=32
C = (5/9)*(F-32)         /* Fahrenheit to Centigrade */

a=3
a= 10*(10*(10*(a+7)))        /*  nested parentheses  */

m=3
b=9
x=7
 y = m*x + b                /*  2-D line  */