The calculator COBOL program used in the sample service is:
$set intlevel(4)
identification division.
program-id. calculate.
environment division.
data division.
working-storage section.
01 calmemory pic s9(9) comp-5 value 0.
linkage section.
01 calculator.
05 arg1 pic s9(19)v9(19) comp-3.
05 arg2 pic s9(19)v9(19) comp-3.
05 result pic s9(19)v9(19) comp-3.
05 storage pic s9(19)v9(19) comp-3.
procedure division.
exit program.
entry "add" using calculator.
move arg1 to result
add arg2 to result
add result to calmemory
move calmemory to storage
exit program.
entry "subtract" using calculator.
move arg1 to result
subtract arg2 from result
add result to calmemory
move calmemory to storage
exit program.
entry "multiply" using calculator.
move arg1 to result
multiply arg2 by result
add result to calmemory
move calmemory to storage
exit program.
entry "divide" using calculator.
move arg1 to result
divide arg2 into result
add result to calmemory
move calmemory to storage
exit program.