if { [isdraw result] } {
    #check if result is valid

    puts "checkshape"
    set ch [checkshape result]
    puts $ch

    if {[info exists command] && ${command} == "mkvolume"} {
        set bcheck [bopcheck result]
        puts $bcheck
        if {![regexp {This shape seems to be OK.} $bcheck]} {
            puts "Error: bopcheck failed"
        }
    }

    if { [info exists nbsh_v ] } {
        set arr_v [explode result v]
        set nb_v [ llength $arr_v ]
        if { $nb_v != $nbsh_v } {
            puts "Error : The resulting shape is WRONG because it must contain $nbsh_v vertexes instead of $nb_v"
        } else {
            puts "The resulting 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 : The resulting shape is WRONG because it must contain $nbsh_e edges instead of $nb_e"
        } else {
            puts "The resulting shape contains $nb_e edges"
        }
    }

   smallview
   if { [info exists display_vertices ] } {
     regexp {Mass +: +([-0-9.+eE]+)} [lprops result] full mass
   } else {
     regexp {Mass +: +([-0-9.+eE]+)} [sprops result] full mass
   }
   if { [expr $mass != 0] || [info exists show_only_result]} {
     donly result
     if { [info exists nbsh_v ] } {
       explode result v
     }
   } elseif { [isdraw a] || [isdraw b]} {
     donly a b
   }
   fit
   xwd $imagedir/${test_image}.png
}
# to end a test script
puts "TEST COMPLETED"