HP 48GX IFT Error: Too Few Arguments

[Giuseppe Donnini]

(06-17-2021 01:46 AM)MNH Wrote:  I'm following the IFT command syntax.

You are not. For IFT to work properly, the then-sequence, that is, in your case, the CALC program, must be present on the stack as an argument. So, instead of evaluating CALC, you have to recall it to the stack, by doing 'CALC' RCL. If the flag is true, IFT will evaluate the program; otherwise, the program will simply be dropped from the stack.

Anyhow, in the present context, there is no particular advantage to using the RPN command form rather than the normal IF 9 FS? THEN CALC END form; the latter would even be shorter by 2.5 bytes.