There are two display modes\&. The first, multiline mode, is the
default\&. It only works if the \fBTERM\fP parameter is set to a valid
terminal type that can move the cursor up\&. The second, single line
mode, is used if \fBTERM\fP is invalid or incapable of moving the
cursor up, or if the \fBSINGLE_LINE_ZLE\fP option is set\&.