Калькулятор линейных выражений с интерфейсом на Batch

@(
    call=Echo Off
);
SetLocal
 
Set "Core=%extd%"
Set "WindowTitle=Calculator"
 
call:extd /InputBox "%WindowTitle%" "Enter math example for solution:" ""
call:extd /Trim "%result%" " "
If "%result%"=="" (Call :EmptyData & EndLocal & Exit /b 1);
Set /a "answer=%result%"
If "%answer%"=="" (Call :WrongFormat & EndLocal & Exit /b 1)
Echo [V] Example ^> %result%
Echo     Answer  ^> %answer%
call:extd /MessageBox "%WindowTitle%" "Answer: %answer%. Copy the result?" "4"
If "%result%"=="6" (
    call:extd /SetClipboardText %answer%
    Echo [V] Answer copied to clipboard.
);
Echo [V] Closing the program...
EndLocal
Exit /b 0
 
:EmptyData
Echo [X] Input data error.
call:extd /MessageBox "%WindowTitle%" "You haven't entered an example to solve it!" "16"
Exit /b
 
:WrongFormat
Echo [X] Error processing input data.
call:extd /MessageBox "%WindowTitle%" "Invalid math example format. Check for correctness and try again." "16"
Exit /b