DIFFERENCE( ) Function Example
STORE 'Smith' TO gcName1
STORE 'Smythe' TO gcName2
STORE 'Smittie' TO gcName3
STORE '' TO gcName4
CLEAR
? DIFFERENCE(gcName1, gcName2) && Displays 4
? DIFFERENCE(gcName1, gcName3) && Displays 4
? DIFFERENCE(gcName1, gcName4) && Displays 1