Format empty arrays using ↕, not ⥊

3 files changed, 90 insertions, 90 deletions

diff --git a/docs/bqn.js b/docs/bqn.js
index dc51c549..afc4d87b 100644
--- a/docs/bqn.js
+++ b/docs/bqn.js
@@ -195,9 +195,9 @@ let fmt0 = x =>
     (x.glyph||(x.m?"*"+x.m+"-modifier*":"*function*"))
   : ""+x;
 let fmt1 = run(
-  new Uint8Array([15,1,25,21,0,1,22,0,2,11,14,0,60,0,14,0,17,0,17,19,0,36,0,61,8,3,2,0,39,0,9,0,36,0,52,8,8,21,0,2,3,2,0,39,0,52,0,37,0,7,8,8,0,18,9,22,0,3,11,14,15,2,22,0,4,11,14,0,10,0,7,0,46,19,0,41,15,3,8,22,0,5,11,14,15,4,22,0,6,11,14,15,5,22,0,7,11,14,15,6,15,7,3,2,0,39,15,8,0,45,3,2,0,39,0,9,0,37,0,9,0,36,0,45,8,0,35,0,6,8,8,8,8,22,0,8,11,14,0,70,0,18,0,69,17,15,9,15,10,3,2,0,39,0,9,0,10,0,42,19,0,6,0,10,0,9,0,46,19,19,8,3,2,0,39,0,13,0,13,0,42,0,42,3,2,19,8,22,0,9,11,14,15,11,22,0,10,11,14,15,12,22,0,11,11,14,15,13,15,14,15,15,3,3,0,39,0,26,0,52,7,0,7,0,16,19,0,34,0,31,0,0,7,0,11,0,0,0,7,0,36,0,42,8,19,0,9,19,8,8,22,0,12,11,14,21,0,3,21,0,12,21,0,11,3,3,0,39,0,12,0,3,0,46,19,8,22,0,13,11,14,21,0,13,0,34,0,28,0,51,0,0,0,52,17,0,37,0,17,8,7,8,0,16,9,0,20,0,43,19,25,0,45,0,29,0,19,7,21,0,1,0,1,16,17,0,22,0,38,0,33,0,27,0,30,0,2,7,7,7,8,16,0,31,0,43,0,44,3,2,0,40,0,0,8,7,21,0,2,17,0,16,16,0,25,0,36,0,43,8,0,38,0,42,8,16,25,21,0,1,0,13,16,0,20,0,43,17,22,0,3,11,0,4,0,45,17,21,1,4,16,22,0,4,11,14,15,16,22,0,5,11,14,21,0,1,0,16,21,0,1,0,13,16,0,19,0,43,17,0,17,21,0,3,0,31,0,2,7,16,17,17,0,19,0,36,0,31,0,0,7,8,21,0,5,3,2,0,39,0,15,0,34,0,9,8,0,7,0,42,19,8,21,0,4,17,25,21,0,1,0,16,16,0,29,0,26,0,53,7,0,16,0,13,0,25,0,43,19,0,37,0,17,8,19,0,17,0,15,19,7,21,0,1,0,13,16,21,1,4,0,45,17,17,0,17,16,25,0,53,0,16,21,0,1,0,9,16,21,0,2,3,2,17,22,0,3,11,14,21,0,3,21,0,1,21,0,3,3,3,0,18,16,0,17,16,25,0,64,0,17,21,0,1,0,24,16,0,20,0,45,17,0,20,0,43,17,17,0,17,0,63,17,0,18,16,25,21,0,1,0,13,16,0,25,0,43,17,22,0,3,11,14,0,65,21,0,2,0,15,0,3,0,45,19,0,27,0,24,7,0,66,19,0,16,9,21,1,2,3,2,0,39,0,7,0,36,0,47,8,8,16,3,2,0,17,16,0,19,21,0,3,17,0,18,16,21,0,1,0,25,0,38,0,67,0,25,0,45,0,1,21,0,2,17,0,3,0,48,17,0,4,0,42,17,17,8,16,0,68,0,19,0,36,0,1,8,21,0,3,17,0,18,16,3,3,0,17,16,25,21,0,1,0,24,16,0,30,0,10,7,0,62,17,0,32,0,1,7,16,0,33,0,0,7,16,0,10,0,46,17,0,31,0,6,7,16,25,21,0,1,0,29,0,71,7,16,21,1,7,0,45,17,21,1,8,0,46,17,0,25,0,36,0,42,0,43,3,2,8,0,38,0,54,8,16,25,21,0,1,0,13,16,0,72,0,29,21,1,2,7,0,29,0,73,0,37,0,17,8,7,9,0,17,9,0,25,0,36,0,43,8,0,38,0,55,8,9,3,2,0,39,0,9,0,7,0,45,19,8,16,0,27,0,17,7,0,62,17,0,18,16,25,21,0,1,0,29,0,13,7,16,22,0,3,11,14,21,0,3,0,29,0,25,7,0,45,17,0,16,0,26,0,45,7,0,1,0,10,19,0,41,0,32,0,4,7,8,3,2,0,39,0,10,0,7,0,42,19,8,16,22,0,4,11,14,21,0,3,0,29,0,25,7,16,0,10,0,7,0,42,19,0,41,0,45,0,40,0,32,0,4,7,8,8,16,22,0,5,11,14,21,0,1,0,29,0,19,7,0,45,0,19,21,0,4,0,9,16,0,2,21,0,2,17,0,1,16,17,0,5,21,0,4,17,0,2,21,0,2,17,0,30,0,17,7,21,0,5,17,17,0,10,0,1,0,46,19,0,4,0,42,19,0,41,0,18,8,16,0,46,0,40,0,17,0,34,0,7,8,8,16,22,0,6,11,14,21,0,6,21,1,6,0,8,0,34,21,1,5,8,3,2,0,39,21,0,5,0,16,16,0,12,0,36,0,22,0,36,0,45,8,8,16,8,16,21,1,7,0,46,17,25,21,0,1,0,29,21,1,13,7,16,21,1,10,0,45,0,14,21,0,2,17,17,21,1,8,21,0,1,0,10,16,17,25,21,0,1,0,13,16,0,20,0,43,17,22,0,3,11,0,9,16,0,1,16,0,10,0,36,0,42,8,0,41,0,44,8,16,22,0,4,11,14,0,56,22,0,5,11,14,15,17,22,0,6,11,14,21,0,1,0,23,0,36,0,15,0,10,21,0,5,19,0,0,0,45,19,8,21,0,6,3,2,0,39,0,10,0,9,0,45,19,8,16,22,0,1,12,14,21,0,1,0,10,16,22,0,7,11,14,21,0,5,0,19,0,36,0,1,8,21,0,3,17,21,0,4,0,40,0,17,8,21,0,1,17,21,0,4,0,40,0,17,8,0,59,0,19,21,0,3,0,17,0,45,17,0,25,0,43,17,17,0,16,21,0,3,17,0,25,0,38,21,0,5,8,16,17,0,18,16,21,0,7,0,9,0,45,17,0,41,21,1,5,21,1,7,0,45,19,21,1,8,21,0,7,19,8,16,25,21,0,1,21,1,11,21,1,9,3,2,0,39,0,13,0,10,0,42,19,0,31,0,6,7,9,8,16,25,21,0,1,21,1,11,0,43,17,25,21,0,1,0,17,0,36,0,24,0,34,0,29,0,53,7,8,8,16,0,24,21,0,2,0,0,0,45,17,0,17,0,42,17,0,23,16,0,2,0,36,0,7,0,36,0,21,8,8,16,17,25,0,50,0,0,0,52,17,0,7,21,0,1,17,0,2,0,52,0,1,0,58,17,17,0,0,0,49,0,0,0,52,17,0,15,0,1,0,57,19,0,2,0,10,19,21,0,1,17,17,0,0,21,0,1,17,25])
- ,[runtime[0],runtime[1],runtime[2],runtime[6],runtime[7],runtime[9],runtime[11],runtime[12],runtime[13],runtime[14],runtime[15],runtime[16],runtime[18],runtime[19],runtime[20],runtime[21],runtime[22],runtime[23],runtime[24],runtime[25],runtime[26],runtime[29],runtime[30],runtime[32],runtime[35],runtime[36],runtime[43],runtime[44],runtime[45],runtime[46],runtime[47],runtime[49],runtime[50],runtime[51],runtime[52],runtime[53],runtime[54],runtime[55],runtime[56],runtime[58],runtime[59],runtime[61],0,-1,Infinity,1,2,5,4,127,32,10,'
- ,[[0,1,0,0],[1,1,3,14],[0,0,311,3],[0,0,377,6],[0,0,477,3],[0,0,528,4],[0,0,567,3],[0,0,597,4],[0,0,720,3],[0,0,758,3],[0,0,797,3],[0,0,863,7],[0,0,1093,3],[0,0,1126,8],[0,0,1332,3],[0,0,1361,3],[0,0,1371,3],[0,0,1423,3]]
+  new Uint8Array([15,1,25,21,0,1,22,0,2,11,14,0,60,0,14,0,17,0,17,19,0,36,0,61,8,3,2,0,39,0,9,0,36,0,52,8,8,21,0,2,3,2,0,39,0,52,0,37,0,7,8,8,0,18,9,22,0,3,11,14,15,2,22,0,4,11,14,0,10,0,7,0,46,19,0,41,15,3,8,22,0,5,11,14,15,4,22,0,6,11,14,15,5,22,0,7,11,14,15,6,15,7,3,2,0,39,15,8,0,45,3,2,0,39,0,9,0,37,0,9,0,36,0,45,8,0,35,0,6,8,8,8,8,22,0,8,11,14,0,70,0,18,0,69,17,15,9,15,10,3,2,0,39,0,9,0,10,0,42,19,0,6,0,10,0,9,0,46,19,19,8,3,2,0,39,0,13,0,13,0,42,0,42,3,2,19,8,22,0,9,11,14,15,11,22,0,10,11,14,15,12,22,0,11,11,14,15,13,15,14,15,15,3,3,0,39,0,26,0,52,7,0,7,0,16,19,0,34,0,31,0,0,7,0,11,0,0,0,7,0,36,0,42,8,19,0,9,19,8,8,22,0,12,11,14,21,0,3,21,0,12,21,0,11,3,3,0,39,0,12,0,3,0,46,19,8,22,0,13,11,14,21,0,13,0,34,0,28,0,51,0,0,0,52,17,0,37,0,17,8,7,8,0,16,9,0,20,0,43,19,25,0,45,0,29,0,19,7,21,0,1,0,1,16,17,0,22,0,38,0,33,0,27,0,30,0,2,7,7,7,8,16,0,31,0,43,0,44,3,2,0,40,0,0,8,7,21,0,2,17,0,16,16,0,25,0,36,0,43,8,0,38,0,42,8,16,25,21,0,1,0,13,16,0,20,0,43,17,22,0,3,11,0,4,0,45,17,21,1,4,16,22,0,4,11,14,15,16,22,0,5,11,14,21,0,1,0,16,21,0,1,0,13,16,0,19,0,43,17,0,17,21,0,3,0,31,0,2,7,16,17,17,0,19,0,36,0,31,0,0,7,8,21,0,5,3,2,0,39,0,15,0,34,0,9,8,0,7,0,42,19,8,21,0,4,17,25,21,0,1,0,16,16,0,29,0,26,0,53,7,0,16,0,13,0,25,0,43,19,0,37,0,17,8,19,0,17,0,15,19,7,21,0,1,0,13,16,21,1,4,0,45,17,17,0,17,16,25,0,53,0,16,21,0,1,0,9,16,21,0,2,3,2,17,22,0,3,11,14,21,0,3,21,0,1,21,0,3,3,3,0,18,16,0,17,16,25,0,64,0,17,21,0,1,0,24,16,0,20,0,45,17,0,20,0,43,17,17,0,17,0,63,17,0,18,16,25,21,0,1,0,13,16,0,25,0,43,17,22,0,3,11,14,0,65,21,0,2,0,15,0,3,0,45,19,0,27,0,24,7,0,66,19,0,16,9,21,1,2,3,2,0,39,0,7,0,36,0,47,8,8,16,3,2,0,17,16,0,19,21,0,3,17,0,18,16,21,0,1,0,25,0,38,0,67,0,25,0,45,0,1,21,0,2,17,0,3,0,48,17,0,4,0,42,17,17,8,16,0,68,0,19,0,36,0,1,8,21,0,3,17,0,18,16,3,3,0,17,16,25,21,0,1,0,24,16,0,30,0,10,7,0,62,17,0,32,0,1,7,16,0,33,0,0,7,16,0,10,0,46,17,0,31,0,6,7,16,25,21,0,1,0,29,0,71,7,16,21,1,7,0,45,17,21,1,8,0,46,17,0,25,0,36,0,42,0,43,3,2,8,0,38,0,54,8,16,25,21,0,1,0,13,16,0,62,0,29,21,1,2,7,0,29,0,17,0,36,0,72,8,7,9,0,17,9,0,25,0,38,0,55,8,9,3,2,0,39,0,9,0,7,0,45,19,8,16,0,18,16,25,21,0,1,0,29,0,13,7,16,22,0,3,11,14,21,0,3,0,29,0,25,7,0,45,17,0,16,0,26,0,45,7,0,1,0,10,19,0,41,0,32,0,4,7,8,3,2,0,39,0,10,0,7,0,42,19,8,16,22,0,4,11,14,21,0,3,0,29,0,25,7,16,0,10,0,7,0,42,19,0,41,0,45,0,40,0,32,0,4,7,8,8,16,22,0,5,11,14,21,0,1,0,29,0,19,7,0,45,0,19,21,0,4,0,9,16,0,2,21,0,2,17,0,1,16,17,0,5,21,0,4,17,0,2,21,0,2,17,0,30,0,17,7,21,0,5,17,17,0,10,0,1,0,46,19,0,4,0,42,19,0,41,0,18,8,16,0,46,0,40,0,17,0,34,0,7,8,8,16,22,0,6,11,14,21,0,6,21,1,6,0,8,0,34,21,1,5,8,3,2,0,39,21,0,5,0,16,16,0,12,0,36,0,22,0,36,0,45,8,8,16,8,16,21,1,7,0,46,17,25,21,0,1,0,29,21,1,13,7,16,21,1,10,0,45,0,14,21,0,2,17,17,21,1,8,21,0,1,0,10,16,17,25,21,0,1,0,13,16,0,20,0,43,17,22,0,3,11,0,9,16,0,1,16,0,10,0,36,0,42,8,0,41,0,44,8,16,22,0,4,11,14,0,56,22,0,5,11,14,15,17,22,0,6,11,14,21,0,1,0,23,0,36,0,15,0,10,21,0,5,19,0,0,0,45,19,8,21,0,6,3,2,0,39,0,10,0,9,0,45,19,8,16,22,0,1,12,14,21,0,1,0,10,16,22,0,7,11,14,21,0,5,0,19,0,36,0,1,8,21,0,3,17,21,0,4,0,40,0,17,8,21,0,1,17,21,0,4,0,40,0,17,8,0,59,0,19,21,0,3,0,17,0,45,17,0,25,0,43,17,17,0,16,21,0,3,17,0,25,0,38,21,0,5,8,16,17,0,18,16,21,0,7,0,9,0,45,17,0,41,21,1,5,21,1,7,0,45,19,21,1,8,21,0,7,19,8,16,25,21,0,1,21,1,11,21,1,9,3,2,0,39,0,13,0,10,0,42,19,0,31,0,6,7,9,8,16,25,21,0,1,21,1,11,0,43,17,25,21,0,1,0,17,0,36,0,24,0,34,0,29,0,53,7,8,8,16,0,24,21,0,2,0,0,0,45,17,0,17,0,42,17,0,23,16,0,2,0,36,0,7,0,36,0,21,8,8,16,17,25,0,50,0,0,0,52,17,0,7,21,0,1,17,0,2,0,52,0,1,0,58,17,17,0,0,0,49,0,0,0,52,17,0,15,0,1,0,57,19,0,2,0,10,19,21,0,1,17,17,0,0,21,0,1,17,25])
+ ,[runtime[0],runtime[1],runtime[2],runtime[6],runtime[7],runtime[9],runtime[11],runtime[12],runtime[13],runtime[14],runtime[15],runtime[16],runtime[18],runtime[19],runtime[20],runtime[21],runtime[22],runtime[23],runtime[24],runtime[25],runtime[26],runtime[29],runtime[30],runtime[32],runtime[35],runtime[36],runtime[43],runtime[44],runtime[45],runtime[46],runtime[47],runtime[49],runtime[50],runtime[51],runtime[52],runtime[53],runtime[54],runtime[55],runtime[56],runtime[58],runtime[59],runtime[61],0,-1,Infinity,1,2,5,4,127,32,10,'
+ ,[[0,1,0,0],[1,1,3,14],[0,0,311,3],[0,0,377,6],[0,0,477,3],[0,0,528,4],[0,0,567,3],[0,0,597,4],[0,0,720,3],[0,0,758,3],[0,0,797,3],[0,0,850,7],[0,0,1080,3],[0,0,1113,8],[0,0,1319,3],[0,0,1348,3],[0,0,1358,3],[0,0,1410,3]]
 )(a=>str(fmt0(a)));
 let fmt = x => fmt1(x).map(c=>c===0?" ":c).join("");
 
diff --git a/docs/doc/leading.html b/docs/doc/leading.html
index 108b9d63..9e0a182b 100644
--- a/docs/doc/leading.html
+++ b/docs/doc/leading.html
@@ -48,13 +48,13 @@
 </pre>
 <p>In these three cases above, the results are the same as you would get from transposing before and after (this has no effect on the result of <code><span class='Function'>⊏</span><span class='Modifier'>˘</span></code>, since it has rank 1). But in the following cases, the structure is quite different: <code><span class='Function'>↑</span><span class='Value'>a</span></code> is a list of matrices while <code><span class='Function'>↑</span><span class='Modifier'>˘</span><span class='Value'>a</span></code> is a matrix of lists. This is because the functions <code><span class='Function'>⊏</span></code>, <code><span class='Function'>⌽</span></code>, and <code><span class='Function'>⊣</span><span class='Modifier'>`</span></code> leave the trailing axis structure intact (<code><span class='Function'>⊏</span></code> removes one axis); taking into account that Rank or Cells always preserves the leading or frame axes, all axes are preserved (except the one removed by <code><span class='Function'>⊏</span></code>). In contrast, Prefixes or Suffixes pushes some axes down in depth, and the number of axes that are pushed down in this way changes with the rank of application. More precisely, these functions move axes after the first from the argument itself to result elements, and create two axes from the first axis, with one of them forming the sole result axis and the other joining the rest as an element axis.</p>
 <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=4oaRIGEgICAgICAgICAgICAgICAgICAgIyBQcmVmaXhlcyBvZiBhOiAgICByYW5rcyAxfDIK4oaRy5ggYSAgICAgICAgICAgICAgICAgICMgUHJlZml4ZXMgb2Ygcm93czogcmFua3MgMnwxCuKIvsudIGEgICAgICAgICAgICAgICAgICAjIEpvaW4gdGhlIGNlbGxzCuKIvsudy5ggYSAgICAgICAgICAgICAgICAgIyBKb2luLWluc2VydCBpcyBhIG5vLW9wIG9uIGxpc3Rz&run">↗️</a><pre>    <span class='Function'>↑</span> <span class='Value'>a</span>                   <span class='Comment'># Prefixes of a:    ranks 1|2
-</span>┌─                             
-· 0‿2⥊⟨⟩ ┌─     ┌─     ┌─      
-         ╵"ab"  ╵"ab   ╵"ab    
-              ┘   cd"    cd    
-                     ┘   ef"   
-                            ┘  
-                              ┘
+</span>┌─                           
+· ↕0‿2 ┌─     ┌─     ┌─      
+       ╵"ab"  ╵"ab   ╵"ab    
+            ┘   cd"    cd    
+                   ┘   ef"   
+                          ┘  
+                            ┘
     <span class='Function'>↑</span><span class='Modifier'>˘</span> <span class='Value'>a</span>                  <span class='Comment'># Prefixes of rows: ranks 2|1
 </span>┌─             
 ╵ ⟨⟩ "a" "ab"  
diff --git a/docs/doc/prefixes.html b/docs/doc/prefixes.html
index 21bbeff7..5f951c07 100644
--- a/docs/doc/prefixes.html
+++ b/docs/doc/prefixes.html
@@ -99,46 +99,46 @@
 <p>We might view a slice as a selection for not two but <em>three</em> parameters: the number of cells before, in, and after the slice. The conditions are that each parameter, being a length, is at least 0, and the total of the three parameters is equal to the array length. With three parameters and one equality constraint, the space of slices is two-dimensional; the above ways to enumerate it each pick two parameters and allow the third to be dependent on these two. If you're familiar with <a href="https://en.wikipedia.org/wiki/Barycentric_coordinate_system">barycentric coordinates</a> on a triangle, this should sound very familiar because that's exactly what the three parameters are!</p>
 <p>We might also consider the question of slices along multiple axes. Because axes are orthogonal, we can choose such a slice by independently slicing along each axis. To use the homogeneous shape of arrays as much as possible, the result should still only have two added layers of nesting for the two coordinates we choose, with all possible choices for the first axis along the axes of the outer array and those for the second along the axes of each inner array. Our Windows-based solution adapts to multidimensional arrays easily:</p>
 <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=KCjihpUxK+KJoik84o6JMuKImOKGlcKoPCkgM+KAvzLipYoiYWJjZGVmIg==&run">↗️</a><pre>    <span class='Paren'>((</span><span class='Function'>↕</span><span class='Number'>1</span><span class='Function'>+≢</span><span class='Paren'>)</span><span class='Function'>&lt;</span><span class='Modifier2'>⎉</span><span class='Number'>2</span><span class='Modifier2'>∘</span><span class='Function'>↕</span><span class='Modifier'>¨</span><span class='Function'>&lt;</span><span class='Paren'>)</span> <span class='Number'>3</span><span class='Ligature'>‿</span><span class='Number'>2</span><span class='Function'>⥊</span><span class='String'>&quot;abcdef&quot;</span>
-┌─                                           
-╵ ┌─           ┌─                ┌─          
-  ╵ ┌┐ ┌┐ ┌┐   ╵ 0‿1⥊⟨⟩ 0‿1⥊⟨⟩   ╵ 0‿2⥊⟨⟩    
-    └┘ └┘ └┘     0‿1⥊⟨⟩ 0‿1⥊⟨⟩     0‿2⥊⟨⟩    
-    ┌┐ ┌┐ ┌┐     0‿1⥊⟨⟩ 0‿1⥊⟨⟩     0‿2⥊⟨⟩    
-    └┘ └┘ └┘     0‿1⥊⟨⟩ 0‿1⥊⟨⟩     0‿2⥊⟨⟩    
-    ┌┐ ┌┐ ┌┐                   ┘          ┘  
-    └┘ └┘ └┘                                 
-    ┌┐ ┌┐ ┌┐                                 
-    └┘ └┘ └┘                                 
-             ┘                               
-  ┌─           ┌─                ┌─          
-  ╵ ┌┐ ┌┐ ┌┐   ╵ ┌─    ┌─        ╵ ┌─        
-    ╵  ╵  ╵      ╵"a"  ╵"b"        ╵"ab"     
-     ┘  ┘  ┘         ┘     ┘            ┘    
-    ┌┐ ┌┐ ┌┐     ┌─    ┌─          ┌─        
-    ╵  ╵  ╵      ╵"c"  ╵"d"        ╵"cd"     
-     ┘  ┘  ┘         ┘     ┘            ┘    
-    ┌┐ ┌┐ ┌┐     ┌─    ┌─          ┌─        
-    ╵  ╵  ╵      ╵"e"  ╵"f"        ╵"ef"     
-     ┘  ┘  ┘         ┘     ┘            ┘    
-             ┘               ┘            ┘  
-  ┌─           ┌─                ┌─          
-  ╵ ┌┐ ┌┐ ┌┐   ╵ ┌─    ┌─        ╵ ┌─        
-    ╵  ╵  ╵      ╵"a   ╵"b         ╵"ab      
-                   c"    d"          cd"     
-     ┘  ┘  ┘         ┘     ┘            ┘    
-    ┌┐ ┌┐ ┌┐     ┌─    ┌─          ┌─        
-    ╵  ╵  ╵      ╵"c   ╵"d         ╵"cd      
-                   e"    f"          ef"     
-     ┘  ┘  ┘         ┘     ┘            ┘    
-             ┘               ┘            ┘  
-  ┌─           ┌─                ┌─          
-  ╵ ┌┐ ┌┐ ┌┐   ╵ ┌─    ┌─        ╵ ┌─        
-    ╵  ╵  ╵      ╵"a   ╵"b         ╵"ab      
-                   c     d           cd      
-                   e"    f"          ef"     
-     ┘  ┘  ┘         ┘     ┘            ┘    
-             ┘               ┘            ┘  
-                                            ┘
+┌─                                         
+╵ ┌─           ┌─              ┌─          
+  ╵ ┌┐ ┌┐ ┌┐   ╵ ↕0‿1 ↕0‿1     ╵ ↕0‿2      
+    └┘ └┘ └┘     ↕0‿1 ↕0‿1       ↕0‿2      
+    ┌┐ ┌┐ ┌┐     ↕0‿1 ↕0‿1       ↕0‿2      
+    └┘ └┘ └┘     ↕0‿1 ↕0‿1       ↕0‿2      
+    ┌┐ ┌┐ ┌┐               ┘          ┘    
+    └┘ └┘ └┘                               
+    ┌┐ ┌┐ ┌┐                               
+    └┘ └┘ └┘                               
+             ┘                             
+  ┌─           ┌─              ┌─          
+  ╵ ┌┐ ┌┐ ┌┐   ╵ ┌─    ┌─      ╵ ┌─        
+    ╵  ╵  ╵      ╵"a"  ╵"b"      ╵"ab"     
+     ┘  ┘  ┘         ┘     ┘          ┘    
+    ┌┐ ┌┐ ┌┐     ┌─    ┌─        ┌─        
+    ╵  ╵  ╵      ╵"c"  ╵"d"      ╵"cd"     
+     ┘  ┘  ┘         ┘     ┘          ┘    
+    ┌┐ ┌┐ ┌┐     ┌─    ┌─        ┌─        
+    ╵  ╵  ╵      ╵"e"  ╵"f"      ╵"ef"     
+     ┘  ┘  ┘         ┘     ┘          ┘    
+             ┘               ┘          ┘  
+  ┌─           ┌─              ┌─          
+  ╵ ┌┐ ┌┐ ┌┐   ╵ ┌─    ┌─      ╵ ┌─        
+    ╵  ╵  ╵      ╵"a   ╵"b       ╵"ab      
+                   c"    d"        cd"     
+     ┘  ┘  ┘         ┘     ┘          ┘    
+    ┌┐ ┌┐ ┌┐     ┌─    ┌─        ┌─        
+    ╵  ╵  ╵      ╵"c   ╵"d       ╵"cd      
+                   e"    f"        ef"     
+     ┘  ┘  ┘         ┘     ┘          ┘    
+             ┘               ┘          ┘  
+  ┌─           ┌─              ┌─          
+  ╵ ┌┐ ┌┐ ┌┐   ╵ ┌─    ┌─      ╵ ┌─        
+    ╵  ╵  ╵      ╵"a   ╵"b       ╵"ab      
+                   c     d         cd      
+                   e"    f"        ef"     
+     ┘  ┘  ┘         ┘     ┘          ┘    
+             ┘               ┘          ┘  
+                                          ┘
 </pre>
 <p>This array can be <a href="join.html">joined</a>, indicating that the length of each inner axis depends only on the position in the corresponding outer axis (let's also drop those empty slices to take up less space).</p>
 <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=4oi+IDHigL8xIOKGkyAoKOKGlTEr4omiKTzijoky4oiY4oaVwqg8KSAz4oC/MuKliiJhYmNkZWYi&run">↗️</a><pre>    <span class='Function'>∾</span> <span class='Number'>1</span><span class='Ligature'>‿</span><span class='Number'>1</span> <span class='Function'>↓</span> <span class='Paren'>((</span><span class='Function'>↕</span><span class='Number'>1</span><span class='Function'>+≢</span><span class='Paren'>)</span><span class='Function'>&lt;</span><span class='Modifier2'>⎉</span><span class='Number'>2</span><span class='Modifier2'>∘</span><span class='Function'>↕</span><span class='Modifier'>¨</span><span class='Function'>&lt;</span><span class='Paren'>)</span> <span class='Number'>3</span><span class='Ligature'>‿</span><span class='Number'>2</span><span class='Function'>⥊</span><span class='String'>&quot;abcdef&quot;</span>
@@ -171,44 +171,44 @@
 <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=UHJlZnMg4oaQICjihpUxK+KJoinihpHCqDwKU3VmZnMg4oaQICjihpUxK+KJoinihpPCqDwKUHJlZnPCqFN1ZmZzIDPigL8y4qWKImFiY2RlZiI=&run">↗️</a><pre>    <span class='Function'>Prefs</span> <span class='Gets'>←</span> <span class='Paren'>(</span><span class='Function'>↕</span><span class='Number'>1</span><span class='Function'>+≢</span><span class='Paren'>)</span><span class='Function'>↑</span><span class='Modifier'>¨</span><span class='Function'>&lt;</span>
     <span class='Function'>Suffs</span> <span class='Gets'>←</span> <span class='Paren'>(</span><span class='Function'>↕</span><span class='Number'>1</span><span class='Function'>+≢</span><span class='Paren'>)</span><span class='Function'>↓</span><span class='Modifier'>¨</span><span class='Function'>&lt;</span>
     <span class='Function'>Prefs</span><span class='Modifier'>¨</span><span class='Function'>Suffs</span> <span class='Number'>3</span><span class='Ligature'>‿</span><span class='Number'>2</span><span class='Function'>⥊</span><span class='String'>&quot;abcdef&quot;</span>
-┌─                                           
-╵ ┌─                   ┌─            ┌─      
-  ╵ ┌┐ 0‿1⥊⟨⟩ 0‿2⥊⟨⟩   ╵ ┌┐ 0‿1⥊⟨⟩   ╵ ┌┐    
-    └┘                   └┘            └┘    
-    ┌┐ ┌─     ┌─         ┌┐ ┌─         ┌┐    
-    ╵  ╵"a"   ╵"ab"      ╵  ╵"b"       ╵     
-     ┘     ┘       ┘      ┘     ┘       ┘    
-    ┌┐ ┌─     ┌─         ┌┐ ┌─         ┌┐    
-    ╵  ╵"a    ╵"ab       ╵  ╵"b        ╵     
-         c"     cd"           d"             
-     ┘     ┘       ┘      ┘     ┘       ┘    
-    ┌┐ ┌─     ┌─         ┌┐ ┌─         ┌┐    
-    ╵  ╵"a    ╵"ab       ╵  ╵"b        ╵     
-         c      cd            d              
-         e"     ef"           f"             
-     ┘     ┘       ┘      ┘     ┘       ┘    
-                     ┘             ┘      ┘  
-  ┌─                   ┌─            ┌─      
-  ╵ ┌┐ 0‿1⥊⟨⟩ 0‿2⥊⟨⟩   ╵ ┌┐ 0‿1⥊⟨⟩   ╵ ┌┐    
-    └┘                   └┘            └┘    
-    ┌┐ ┌─     ┌─         ┌┐ ┌─         ┌┐    
-    ╵  ╵"c"   ╵"cd"      ╵  ╵"d"       ╵     
-     ┘     ┘       ┘      ┘     ┘       ┘    
-    ┌┐ ┌─     ┌─         ┌┐ ┌─         ┌┐    
-    ╵  ╵"c    ╵"cd       ╵  ╵"d        ╵     
-         e"     ef"           f"             
-     ┘     ┘       ┘      ┘     ┘       ┘    
-                     ┘             ┘      ┘  
-  ┌─                   ┌─            ┌─      
-  ╵ ┌┐ 0‿1⥊⟨⟩ 0‿2⥊⟨⟩   ╵ ┌┐ 0‿1⥊⟨⟩   ╵ ┌┐    
-    └┘                   └┘            └┘    
-    ┌┐ ┌─     ┌─         ┌┐ ┌─         ┌┐    
-    ╵  ╵"e"   ╵"ef"      ╵  ╵"f"       ╵     
-     ┘     ┘       ┘      ┘     ┘       ┘    
-                     ┘             ┘      ┘  
-  ┌─                   ┌─            ┌─      
-  ╵ ┌┐ 0‿1⥊⟨⟩ 0‿2⥊⟨⟩   ╵ ┌┐ 0‿1⥊⟨⟩   ╵ ┌┐    
-    └┘                   └┘            └┘    
-                     ┘             ┘      ┘  
-                                            ┘
+┌─                                         
+╵ ┌─                  ┌─           ┌─      
+  ╵ ┌┐ ↕0‿1  ↕0‿2     ╵ ┌┐ ↕0‿1    ╵ ┌┐    
+    └┘                  └┘           └┘    
+    ┌┐ ┌─    ┌─         ┌┐ ┌─        ┌┐    
+    ╵  ╵"a"  ╵"ab"      ╵  ╵"b"      ╵     
+     ┘     ┘      ┘      ┘     ┘      ┘    
+    ┌┐ ┌─    ┌─         ┌┐ ┌─        ┌┐    
+    ╵  ╵"a   ╵"ab       ╵  ╵"b       ╵     
+         c"    cd"           d"            
+     ┘     ┘      ┘      ┘     ┘      ┘    
+    ┌┐ ┌─    ┌─         ┌┐ ┌─        ┌┐    
+    ╵  ╵"a   ╵"ab       ╵  ╵"b       ╵     
+         c     cd            d             
+         e"    ef"           f"            
+     ┘     ┘      ┘      ┘     ┘      ┘    
+                    ┘            ┘      ┘  
+  ┌─                  ┌─           ┌─      
+  ╵ ┌┐ ↕0‿1  ↕0‿2     ╵ ┌┐ ↕0‿1    ╵ ┌┐    
+    └┘                  └┘           └┘    
+    ┌┐ ┌─    ┌─         ┌┐ ┌─        ┌┐    
+    ╵  ╵"c"  ╵"cd"      ╵  ╵"d"      ╵     
+     ┘     ┘      ┘      ┘     ┘      ┘    
+    ┌┐ ┌─    ┌─         ┌┐ ┌─        ┌┐    
+    ╵  ╵"c   ╵"cd       ╵  ╵"d       ╵     
+         e"    ef"           f"            
+     ┘     ┘      ┘      ┘     ┘      ┘    
+                    ┘            ┘      ┘  
+  ┌─                  ┌─           ┌─      
+  ╵ ┌┐ ↕0‿1  ↕0‿2     ╵ ┌┐ ↕0‿1    ╵ ┌┐    
+    └┘                  └┘           └┘    
+    ┌┐ ┌─    ┌─         ┌┐ ┌─        ┌┐    
+    ╵  ╵"e"  ╵"ef"      ╵  ╵"f"      ╵     
+     ┘     ┘      ┘      ┘     ┘      ┘    
+                    ┘            ┘      ┘  
+  ┌─                  ┌─           ┌─      
+  ╵ ┌┐ ↕0‿1 ↕0‿2      ╵ ┌┐ ↕0‿1    ╵ ┌┐    
+    └┘                  └┘           └┘    
+                 ┘              ┘       ┘  
+                                          ┘
 </pre>