if { [isdraw result] } {
   #check if result is valid
   
   puts "checkshape"
   set ch [checkshape result]
   puts $ch
   
   if { [info exists square] } {
      set prop "square"
      set mass $square
      regexp {Mass +: +([-0-9.+eE]+)} [sprops result] full m      
   }
   if { [info exists length] } {
      set prop "length"
      set mass $length
      regexp {Mass +: +([-0-9.+eE]+)} [lprops result] full m      

      puts "checksection"
      puts [checksection result]
   }

   #if mass (length or square) is empty in test case then result should be an empty shape.
   if { [string compare "$mass" "empty"] != 0 } {
      if { $m == 0 } {
       	 puts "Error : The $command is not valid. The $prop is 0."
      }
      if { $mass > 0 } {
      	 puts "The expected $prop is $mass"
      }
      #check of change of square is < 1%
      if { ($mass != 0 && [expr abs($mass - $m)/$mass] > 0.01) || ($mass == 0 && $m != 0) } {
      	 puts "Error : The $prop of result shape is $m"
      }
      
      if { [info exists nbsh_v ] } {
	set arr_v [explode result v]
	set nb_v [ llength $arr_v ]
        if { $nb_v != $nbsh_v } {
           puts "Error : Result shape is WRONG because it must contain $nbsh_v vertexes instead of $nb_v"
        } else {
           puts "Result shape contains $nb_v vertexes"
        }
        
      }

      if { [info exists nbsh_e ] } {
	set arr_e [explode result e]
	set nb_e [ llength $arr_e ]
        if { $nb_e != $nbsh_e } {
           puts "Error : Result shape is WRONG because it must contain $nbsh_e edges instead of $nb_e"
        } else {
           puts "Result shape contains $nb_e edges"
        }
      }
   } else {
      if { $m != 0 } {
       	 puts "Error : The $command is not valid. The $prop is $m"
      }
   }

   smallview
   if { $m > 0 } {
      donly result
      if { [info exists nbsh_v ] } {
         explode result v
      }
   } else {
      donly a b
   }
   fit
   xwd $imagedir/${test_image}.gif
} else {
   puts "Error : The $command can not be build."
}

# to end a test script
puts "TEST COMPLETED"