diff --git a/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelateGeometry.java b/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelateGeometry.java
index 7fc6dbb8b..005ddd618 100644
--- a/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelateGeometry.java
+++ b/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelateGeometry.java
@@ -49,7 +49,6 @@ public static String name(boolean isA) {
   private boolean isPrepared = false;
   
   private int geomDim = Dimension.FALSE;
-  private List<Coordinate> pts;
   private Set<Coordinate> uniquePoints;
   private BoundaryNodeRule boundaryNodeRule;
   private RelatePointLocator locator;
@@ -120,28 +119,32 @@ private void analyzeDimensions() {
   }
   
   /**
-   * Tests if geometry linear elements are zero-length.
-   * The test is optimized to 
-   * avoid computing length in the common case, since that is expensive.
+   * Tests if all geometry linear elements are zero-length.
+   * For efficiency the test avoids computing actual length.
    * 
    * @param geom
    * @return
    */
-  private boolean isZeroLength(Geometry geom) {
+  private static boolean isZeroLength(Geometry geom) {
     Iterator geomi = new GeometryCollectionIterator(geom);
     while (geomi.hasNext()) {
       Geometry elem = (Geometry) geomi.next();
       if (elem instanceof LineString) {
-        LineString line = (LineString) elem;
-        if (line.getNumPoints() >= 2) {
-          Coordinate p0 = line.getCoordinateN(0);
-          Coordinate p1 = line.getCoordinateN(1);
-          //-- the usual non-zero-length case will have first two points non-equal
-          if (! p0.equals2D(p1) 
-              || line.getLength() > 0) {
-            return false;
-          }
-        }
+        if (! isZeroLength((LineString) elem))
+          return false;
+      }
+    }
+    return true;
+  }
+
+  private static boolean isZeroLength(LineString line) {
+    if (line.getNumPoints() >= 2) {
+      Coordinate p0 = line.getCoordinateN(0);
+      for (int i = 0 ; i < line.getNumPoints(); i++) {
+        Coordinate pi = line.getCoordinateN(1);
+        //-- most non-zero-len lines will trigger this right away 
+        if (! p0.equals2D(pi)) 
+          return false;
       }
     }
     return true;
@@ -173,7 +176,7 @@ public boolean hasDimension(int dim) {
     return false;
   }
   
-  public int getDimensionEffective() {
+  public int getDimensionReal() {
     if (isGeomEmpty) return Dimension.FALSE;
     if (getDimension() == 1 && isLineZeroLen)
       return Dimension.P;
@@ -274,7 +277,7 @@ private Set<Coordinate> createUniquePoints() {
   public List<Point> getEffectivePoints() {
     List<Point> ptListAll = PointExtracter.getPoints(geom);
     
-    if (getDimensionEffective() <= Dimension.P)
+    if (getDimensionReal() <= Dimension.P)
       return ptListAll;
     
     //-- only return Points not covered by another element
diff --git a/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelateNG.java b/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelateNG.java
index 756281122..6fb4cf3d5 100644
--- a/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelateNG.java
+++ b/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelateNG.java
@@ -227,8 +227,8 @@ public boolean evaluate(Geometry b, TopologyPredicate predicate) {
       //TODO: what if predicate is disjoint?  Perhaps use result on disjoint envs?
       return finishValue(predicate);
     }
-    int dimA = geomA.getDimensionEffective();
-    int dimB = geomB.getDimensionEffective();
+    int dimA = geomA.getDimensionReal();
+    int dimB = geomB.getDimensionReal();
     
     //-- check if predicate is determined by dimension or envelope
     predicate.init(dimA, dimB);
@@ -307,19 +307,19 @@ private void computePP(RelateGeometry geomB, TopologyComputer topoComputer) {
     }
   }  
 
-  private void computeAtPoints(RelateGeometry geomSrc, boolean isA, 
+  private void computeAtPoints(RelateGeometry geom, boolean isA, 
       RelateGeometry geomTarget, TopologyComputer topoComputer) {
     
     boolean isResultKnown = false;
-    isResultKnown = computePoints(geomSrc, isA, geomTarget, topoComputer);
+    isResultKnown = computePoints(geom, isA, geomTarget, topoComputer);
     if (isResultKnown) 
       return;
     
-    isResultKnown = computeLineEnds(geomSrc, isA, geomTarget, topoComputer);
+    isResultKnown = computeLineEnds(geom, isA, geomTarget, topoComputer);
     if (isResultKnown) 
       return;
     
-    computeAreaVertices(geomSrc, isA, geomTarget, topoComputer);
+    computeAreaVertex(geom, isA, geomTarget, topoComputer);
   }
   
   private boolean computePoints(RelateGeometry geom, boolean isA, RelateGeometry geomTarget,
@@ -364,7 +364,7 @@ private boolean computeLineEnds(RelateGeometry geom, boolean isA, RelateGeometry
         continue;
       
       if (elem instanceof LineString) {
-        //-- once an intersection with target exterior is recorded, skip further known exterior points
+        //-- once an intersection with target exterior is recorded, skip further known-exterior points
         if (hasExteriorIntersection 
             && elem.getEnvelopeInternal().disjoint(geomTarget.getEnvelope()))
           continue;
@@ -400,7 +400,7 @@ private boolean computeLineEnd(RelateGeometry geom, boolean isA, Coordinate pt,
     return locTarget == Location.EXTERIOR;
   }
 
-  private boolean computeAreaVertices(RelateGeometry geom, boolean isA, RelateGeometry geomTarget, TopologyComputer topoComputer) {
+  private boolean computeAreaVertex(RelateGeometry geom, boolean isA, RelateGeometry geomTarget, TopologyComputer topoComputer) {
     if (! geom.hasDimension(Dimension.A)) {
       return false;
     }
@@ -416,7 +416,7 @@ private boolean computeAreaVertices(RelateGeometry geom, boolean isA, RelateGeom
         continue;
       
       if (elem instanceof Polygon) {
-        //-- once an intersection with target exterior is recorded, skip further known exterior points
+        //-- once an intersection with target exterior is recorded, skip further known-exterior points
         if (hasExteriorIntersection 
             && elem.getEnvelopeInternal().disjoint(geomTarget.getEnvelope()))
           continue;
diff --git a/modules/core/src/main/java/org/locationtech/jts/operation/relateng/TopologyComputer.java b/modules/core/src/main/java/org/locationtech/jts/operation/relateng/TopologyComputer.java
index e72e19094..06f686ed8 100644
--- a/modules/core/src/main/java/org/locationtech/jts/operation/relateng/TopologyComputer.java
+++ b/modules/core/src/main/java/org/locationtech/jts/operation/relateng/TopologyComputer.java
@@ -39,44 +39,44 @@ public TopologyComputer(TopologyPredicate predicate, RelateGeometry geomA, Relat
   }
 
   /**
-   * Determine partial topology in the EXTERIORs a priori.
+   * Determine a priori partial EXTERIOR topology based on dimensions.
    */
   private void initExteriorDims() {
-    int dimAEff = geomA.getDimensionEffective();
-    int dimBEff = geomB.getDimensionEffective();
+    int dimRealA = geomA.getDimensionReal();
+    int dimRealB = geomB.getDimensionReal();
     
     /**
      * For P/L case, P exterior intersects L interior
      */
-    if (dimAEff == Dimension.P && dimBEff == Dimension.L) {
+    if (dimRealA == Dimension.P && dimRealB == Dimension.L) {
       updateDim(Location.EXTERIOR, Location.INTERIOR, Dimension.L);
     }
-    else if (dimAEff == Dimension.L && dimBEff == Dimension.P) {
+    else if (dimRealA == Dimension.L && dimRealB == Dimension.P) {
       updateDim(Location.INTERIOR, Location.EXTERIOR, Dimension.L);
     }
     /**
      * For P/A case, the Area Int and Bdy intersect the Point exterior.
      */
-    else if (dimAEff == Dimension.P && dimBEff == Dimension.A) {
+    else if (dimRealA == Dimension.P && dimRealB == Dimension.A) {
       updateDim(Location.EXTERIOR, Location.INTERIOR, Dimension.A);
       updateDim(Location.EXTERIOR, Location.BOUNDARY, Dimension.L);
     }
-    else if (dimAEff == Dimension.A && dimBEff == Dimension.P) {
+    else if (dimRealA == Dimension.A && dimRealB == Dimension.P) {
       updateDim(Location.INTERIOR, Location.EXTERIOR, Dimension.A);
       updateDim(Location.BOUNDARY, Location.EXTERIOR, Dimension.L);
     }
-    else if (dimAEff == Dimension.L && dimBEff == Dimension.A) {
+    else if (dimRealA == Dimension.L && dimRealB == Dimension.A) {
       updateDim(Location.EXTERIOR, Location.INTERIOR, Dimension.A);
      }
-    else if (dimAEff == Dimension.A && dimBEff == Dimension.L) {
+    else if (dimRealA == Dimension.A && dimRealB == Dimension.L) {
       updateDim(Location.INTERIOR, Location.EXTERIOR, Dimension.A);
     }
     //-- cases where one geom is EMPTY
-    else if (dimAEff == Dimension.FALSE || dimBEff == Dimension.FALSE) {
-      if (dimAEff != Dimension.FALSE) {
+    else if (dimRealA == Dimension.FALSE || dimRealB == Dimension.FALSE) {
+      if (dimRealA != Dimension.FALSE) {
         initExteriorEmpty(RelateGeometry.GEOM_A);
       }
-      if (dimBEff != Dimension.FALSE) {
+      if (dimRealB != Dimension.FALSE) {
         initExteriorEmpty(RelateGeometry.GEOM_B);
       }
     }