Improve description of geometric operators.

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index b81dc923871973eb78ffede94d73974aa396fa82..524542d1df2b9adb4cdc494ac7b8c189e7e34933 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,5 +1,5 @@
 
 
@@ -5436,11 +5436,26 @@ SELECT TIMESTAMP 'now';
    Number of points in path or polygon
    # '((1,0),(0,1),(-1,0))'
        
+       
+    @-@  
+   Length or circumference
+   @-@ path '((0,0),(1,0))'
+       
+       
+    @@ 
+   Center of
+   @@ circle '((0,0),10)'
+       
        
     ## 
    Point of closest proximity
    point '(0,0)' ## lseg '((2,0),(0,2))'
        
+       
+    <-> 
+   Distance between
+   circle '((0,0),1)' <-> circle '((5,0),1)'
+       
        
     && 
    Overlaps?
@@ -5448,82 +5463,82 @@ SELECT TIMESTAMP 'now';
        
        
     &< 
-   Overlaps to left?
+   Overlaps or is left of?
    box '((0,0),(1,1))' &< box '((0,0),(2,2))'
        
        
     &> 
-   Overlaps to right?
+   Overlaps or is right of?
    box '((0,0),(3,3))' &> box '((0,0),(2,2))'
        
-       
-    <-> 
-   Distance between
-   circle '((0,0),1)' <-> circle '((5,0),1)'
-       
        
     << 
    Left of?
    circle '((0,0),1)' << circle '((5,0),1)'
        
-       
-    <^ 
-   Is below?
-   circle '((0,0),1)' <^ circle '((0,5),1)'
-       
        
     >> 
-   Is right of?
+   Right of?
    circle '((5,0),1)' >> circle '((0,0),1)'
        
+       
+    <^ 
+   Below?
+   circle '((0,0),1)' <^ circle '((0,5),1)'
+       
        
     >^ 
-   Is above?
+   Above?
    circle '((0,5),1)' >^ circle '((0,0),1)'
        
        
     ?# 
-   Intersects or overlaps
+   Intersect?
    lseg '((-1,0),(1,0))' ?# box '((-2,-2),(2,2))'
        
        
     ?- 
-   Is horizontal?
-   point '(1,0)' ?- point '(0,0)'
+   Horizontal?
+   ?- lseg '((-1,0),(1,0))'
        
        
-    ?-| 
-   Is perpendicular?
-   lseg '((0,0),(0,1))' ?-| lseg '((0,0),(1,0))'
+    ?- 
+   Horizontally aligned?
+   point '(1,0)' ?- point '(0,0)'
        
        
-    @-@  
-   Length or circumference
-   @-@ path '((0,0),(1,0))'
+    ?| 
+   Vertical?
+   ?| lseg '((-1,0),(1,0))'
        
        
     ?| 
-   Is vertical?
+   Vertically aligned?
    point '(0,1)' ?| point '(0,0)'
        
+       
+    ?-| 
+   Perpendicular?
+   lseg '((0,0),(0,1))' ?-| lseg '((0,0),(1,0))'
+       
        
     ?|| 
-   Is parallel?
+   Parallel?
    lseg '((-1,0),(1,0))' ?|| lseg '((-1,2),(1,2))'
        
        
-    @ 
-   Contained or on
-   point '(1,1)' @ circle '((0,0),2)'
+    ~ 
+   Contains?
+   circle '((0,0),2)' ~ point '(1,1)'
        
        
-    @@ 
-   Center of
-   @@ circle '((0,0),10)'
+    @ 
+   Contained in or on?
+   point '(1,1)' @ circle '((0,0),2)'
        
        
     ~= 
-   Same as
+   Same as?
    polygon '((0,0),(1,1))' ~= polygon '((1,1),(0,0))'