puts "================="
puts "OCC644"
puts "SAM1513"
puts "================="
puts ""

NewDocument D 
UndoLimit D 10 

NewCommand D 
SetVariable D 0:1 0 mm 
SetRelation D 0:2 x=10 0:1 

NewCommand D 
SetRelation D 0:2 x=20 0:1 

NewCommand D 
Undo D 
Redo D
Undo D

set RelationList [DumpRelation D 0:2]

if {[llength ${RelationList}] <= 10} {
    puts "OCC644: OK"
} else {
    puts "OCC644: ERROR"
}