+ set c [lindex $vlastins($view) $ka]
+ if {$c == 0 || [string compare $tok [lindex $varctok($view) $c]] < 0} {
+ set c $ka
+ set b [lindex $vdownptr($view) $ka]
+ } else {
+ set b [lindex $vleftptr($view) $c]
+ }
+ while {$b != 0 && [string compare $tok [lindex $varctok($view) $b]] >= 0} {
+ set c $b
+ set b [lindex $vleftptr($view) $c]
+ }
+ if {$c == $ka} {
+ lset vdownptr($view) $ka $a
+ lappend vbackptr($view) 0
+ } else {
+ lset vleftptr($view) $c $a
+ lappend vbackptr($view) $c
+ }
+ lset vlastins($view) $ka $a
+ lappend vupptr($view) $ka
+ lappend vleftptr($view) $b
+ if {$b != 0} {
+ lset vbackptr($view) $b $a
+ }