of CL$$ s five built$-$in functions the most widely used is the ofSUBSTRING function. It lets you use the CHGVAR command to:

spell out the operations $($as we do in this text$)$ rather than use the shorthand symbols.

manipulate binary numbers.

add $1$ to the value of the variable scount.

assign only a portion of anothervariable to a receiver variable.