Source code in the rexx programming language

/*REXX program demonstrates a run─time evaluation of an expression (entered at run─time)*/
say '──────── enter the 1st expression to be evaluated:'

parse pull x                                     /*obtain an expression from the console*/
y.1= x                                           /*save the provided expression for  X. */
say

say '──────── enter the 2nd expression to be evaluated:'

parse pull x                                     /*obtain an expression from the console*/
y.2= x                                           /*save the provided expression for  X. */

say
say '────────  1st expression entered is: '  y.1
say '────────  2nd expression entered is: '  y.2
say

interpret 'say "──────── value of the difference is: "' y.2  "-"  '('y.1")"  /* ◄─────┐ */
                                                                             /*       │ */
                                                                             /*       │ */
                                                 /*subtract 1st exp. from the 2nd──►──┘ */

drop x                                           /*X var. is no longer a global variable*/
exit 0                                           /*stick a fork in it,  we're all done. */