puts "================"
puts "OCC251: Section of two faces f1 and f2 depends on order of arguments:  section r1 f1 f2 and section r2 f2 f1 give different results, one of result is invalid - overlapped edges."
puts "================"
puts ""

restore [locate_data_file OCC251.brep] f 
explode f
checkshape f_1
checkshape f_2

bsection result f_2 f_1
explode result

foreach a [explode result e] {
  foreach b [explode result e] {
    if { ![regexp {not} [compare b_1 n_1]] } {
      continue;
    }
    
    set coe [checkoverlapedges e1 e2 5.0e-5]

    puts "$a <-> $b: $coe"
    if { [regexp "Edges are not overlapped" $coe] != 1 } {
      puts "Error: $a and $b are overlapped"
    }
  }
}

checkprops result -l 1. 
checkshape result 
checksection result -r 2

smallview
don result*
fit

checkview -screenshot -2d -path ${imagedir}/${test_image}.png