diff --git a/tutorial/t16.geo b/tutorial/t16.geo
index 390e0d81a7362e774f4a340b91647cc017980ee3..b645f42a9b2bb058af62eaf6686862c204203403 100644
--- a/tutorial/t16.geo
+++ b/tutorial/t16.geo
@@ -15,8 +15,8 @@ SetFactory("OpenCASCADE");
 // And let's build the same model as in t5.geo, but using constructive solid
 // geometry:
 
-Block(1) = {0,0,0, 1,1,1};
-Block(2) = {0,0,0, 0.5,0.5,0.5};
+Box(1) = {0,0,0, 1,1,1};
+Box(2) = {0,0,0, 0.5,0.5,0.5};
 BooleanDifference(3) = { Volume{1}; Delete; }{ Volume{2}; Delete; };
 x = 0 ; y = 0.75 ; z = 0 ; r = 0.09 ;
 For t In {1:5}
@@ -26,9 +26,14 @@ For t In {1:5}
 EndFor
 v() = BooleanFragments{ Volume{3}; Delete; }{ Volume{3+1:3+5}; Delete; };
 
-s() = Unique(Abs(Boundary{ Volume{v()}; }));
-l() = Unique(Abs(Boundary{ Surface{s()}; }));
-p() = Unique(Abs(Boundary{ Line{l()}; }));
-Characteristic Length{p()} = 0.055;
+lcar1 = .1;
+lcar2 = .0005;
+lcar3 = .055;
+eps = 1e-3;
+
+Characteristic Length{ PointsOf{ Volume{:}; } } = lcar1;
+Characteristic Length{ PointsOf{ Volume{3+1:3+5}; } } = lcar3;
+p() = Point In BoundingBox{0.5-eps,0.5-eps,0.5-eps,0.5+eps,0.5+eps,0.5+eps};
+Characteristic Length{ p() } = lcar2;
 
 // Additional examples are available in the demos/boolean directory.