BOXCLEAR

The BOXCLEAR expression is used to clear rectangular areas on most terminal types (it is ignored on other terminal types).

The form of the expression is:

   BOXCLEAR(upperleftcol,upperleftrow,lowerright​col,lowerrightrow)

Example:

   PRINT BOXCLEAR(5,5,10,15)

clears a rectangle with the upper left corner at column 5, row 5 and the lower right corner at column 10, row 15, using blank characters.