Letter Function

Definition$/$Explanation

A$-$B: $,$ is$\_$empty$\_$set$($S$)$ set $S$ is not empty set

true if set $S$ is empty set; false if

Write in Python:

the selected function

a program to:

$--$ input$/$read input data from the keyboard,

$--$ call and execute the selected function, and

$--$ output result$/$output data on the screen of terminal.

The function may print$/$report only errors.

The function should not print the computed value.

The function should return the computed value.

The function$($s$)$ and program must be into two separate python files.

The function$($s$)$ and program must be designed from scratch. It is not allowed to use standard and library functions.

A set is a collection of no duplicate elements.

An element is an integer.