5 files changed, 170 insertions, 2 deletions
diff --git a/docs/doc/hook.html b/docs/doc/hook.html
new file mode 100644
index 00000000..22054800
--- /dev/null
+++ b/docs/doc/hook.html
@@ -0,0 +1,161 @@
+<head>
+  <link href="../favicon.ico" rel="shortcut icon" type="image/x-icon"/>
+  <link href="../style.css" rel="stylesheet"/>
+  <title>BQN: Before and After</title>
+</head>
+<div class="nav">(<a href="https://github.com/mlochbaum/BQN">github</a>) / <a href="../index.html">BQN</a> / <a href="index.html">doc</a></div>
+<h1 id="before-and-after"><a class="header" href="#before-and-after">Before and After</a></h1>
+<p>(<a href="https://aplwiki.com/wiki/File:Before_and_after.jpg">This joke</a> has already been claimed by APL, unfortunately)</p>
+<p><em>Also see <a href="../tutorial/combinator.html#before-and-after">this tutorial section</a> for an introduction that doesn't require so much context to understand.</em></p>
+<svg viewBox='-51 0 672 270'>
+  <g font-size='20px' text-anchor='middle' transform='translate(145,20)'>
+    <rect class='code' stroke-width='1' rx='12' x='-120.4' y='1' width='240.8' height='205'/>
+    <text dy='0.32em' y='223' fill='currentColor'>Before</text>
+    <g font-size='21px' font-family='BQN,monospace' transform='translate(-60.87,25)'>
+      <text dy='0.32em' y='155' font-size='19px'><tspan class='Function'>𝔽</tspan><tspan class='Modifier2'>⊸</tspan><tspan class='Function'>𝔾</tspan> <tspan class='Value'>𝕩</tspan></text>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M0 0L-32 57'/>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M-32 57L0 114'/>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M0 0Q41.6 57 0 114'/>
+      <circle r='12' class='code' stroke-width='0' cx='0' cy='0'/>
+      <circle r='12' class='code' stroke-width='0' cx='-32' cy='57'/>
+      <circle r='12' class='code' stroke-width='0' cx='0' cy='114'/>
+      <text dy='0.32em' x='0' y='0'><tspan class='Function'>𝔾</tspan></text>
+      <text dy='0.32em' x='-32' y='57'><tspan class='Function'>𝔽</tspan></text>
+      <text dy='0.32em' x='0' y='114'><tspan class='Value'>𝕩</tspan></text>
+    </g>
+    <g font-size='21px' font-family='BQN,monospace' transform='translate(60.87,25)'>
+      <text dy='0.32em' y='155' font-size='19px'><tspan class='Value'>𝕨</tspan> <tspan class='Function'>𝔽</tspan><tspan class='Modifier2'>⊸</tspan><tspan class='Function'>𝔾</tspan> <tspan class='Value'>𝕩</tspan></text>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M0 0L-32 57'/>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M-32 57L-32 114'/>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M0 0C40 57 32 51.3 32 114'/>
+      <circle r='12' class='code' stroke-width='0' cx='0' cy='0'/>
+      <circle r='12' class='code' stroke-width='0' cx='-32' cy='57'/>
+      <circle r='12' class='code' stroke-width='0' cx='-32' cy='114'/>
+      <circle r='12' class='code' stroke-width='0' cx='32' cy='114'/>
+      <text dy='0.32em' x='0' y='0'><tspan class='Function'>𝔾</tspan></text>
+      <text dy='0.32em' x='-32' y='57'><tspan class='Function'>𝔽</tspan></text>
+      <text dy='0.32em' x='-32' y='114'><tspan class='Value'>𝕨</tspan></text>
+      <text dy='0.32em' x='32' y='114'><tspan class='Value'>𝕩</tspan></text>
+    </g>
+  </g>
+  <g font-size='20px' text-anchor='middle' transform='translate(425,20)'>
+    <rect class='code' stroke-width='1' rx='12' x='-120.4' y='1' width='240.8' height='205'/>
+    <text dy='0.32em' y='223' fill='currentColor'>After</text>
+    <g font-size='21px' font-family='BQN,monospace' transform='translate(-60.87,25)'>
+      <text dy='0.32em' y='155' font-size='19px'><tspan class='Function'>𝔽</tspan><tspan class='Modifier2'>⟜</tspan><tspan class='Function'>𝔾</tspan> <tspan class='Value'>𝕩</tspan></text>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M0 0Q-41.6 57 0 114'/>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M0 0L32 57'/>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M32 57L0 114'/>
+      <circle r='12' class='code' stroke-width='0' cx='0' cy='0'/>
+      <circle r='12' class='code' stroke-width='0' cx='32' cy='57'/>
+      <circle r='12' class='code' stroke-width='0' cx='0' cy='114'/>
+      <text dy='0.32em' x='0' y='0'><tspan class='Function'>𝔽</tspan></text>
+      <text dy='0.32em' x='32' y='57'><tspan class='Function'>𝔾</tspan></text>
+      <text dy='0.32em' x='0' y='114'><tspan class='Value'>𝕩</tspan></text>
+    </g>
+    <g font-size='21px' font-family='BQN,monospace' transform='translate(60.87,25)'>
+      <text dy='0.32em' y='155' font-size='19px'><tspan class='Value'>𝕨</tspan> <tspan class='Function'>𝔽</tspan><tspan class='Modifier2'>⟜</tspan><tspan class='Function'>𝔾</tspan> <tspan class='Value'>𝕩</tspan></text>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M0 0C-40 57 -32 51.3 -32 114'/>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M0 0L32 57'/>
+      <path class='yellow' style='fill:none' stroke-width='2' d='M32 57L32 114'/>
+      <circle r='12' class='code' stroke-width='0' cx='0' cy='0'/>
+      <circle r='12' class='code' stroke-width='0' cx='32' cy='57'/>
+      <circle r='12' class='code' stroke-width='0' cx='-32' cy='114'/>
+      <circle r='12' class='code' stroke-width='0' cx='32' cy='114'/>
+      <text dy='0.32em' x='0' y='0'><tspan class='Function'>𝔽</tspan></text>
+      <text dy='0.32em' x='32' y='57'><tspan class='Function'>𝔾</tspan></text>
+      <text dy='0.32em' x='-32' y='114'><tspan class='Value'>𝕨</tspan></text>
+      <text dy='0.32em' x='32' y='114'><tspan class='Value'>𝕩</tspan></text>
+    </g>
+  </g>
+</svg>
+
+<p>The &quot;hook&quot; combinators Before and After serve a few purposes in BQN. The important thing to remember: the pointy side goes towards the first function to be executed, and the next function that returns the final result is at the ring side. If the pointy-side function is actually a constant like a number, then the ring-side function just gets applied to that constant and one of the arguments. This is the thing Haskell programmers are constantly telling each other isn't called currying, or &quot;Bind&quot; in BQN.</p>
+<table>
+<thead>
+<tr>
+<th>Name</th>
+<th><code><span class='Function'>Cmp</span></code></th>
+<th><code><span class='Function'>Cmp</span> <span class='Value'>𝕩</span></code></th>
+<th><code><span class='Value'>𝕨</span> <span class='Function'>Cmp</span> <span class='Value'>𝕩</span></code></th>
+<th>Unified</th>
+<th>Train</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td>Before</td>
+<td><code><span class='Function'>F</span><span class='Modifier2'>⊸</span><span class='Function'>G</span></code></td>
+<td><code><span class='Paren'>(</span><span class='Function'>F</span><span class='Value'>𝕩</span><span class='Paren'>)</span> <span class='Function'>G</span> <span class='Value'>𝕩</span></code></td>
+<td><code><span class='Paren'>(</span><span class='Function'>F</span><span class='Value'>𝕨</span><span class='Paren'>)</span> <span class='Function'>G</span> <span class='Value'>𝕩</span></code></td>
+<td><code><span class='Brace'>{</span><span class='Paren'>(</span><span class='Function'>𝔽</span><span class='Value'>𝕨</span><span class='Function'>⊣</span><span class='Value'>𝕩</span><span class='Paren'>)</span><span class='Function'>𝔾</span><span class='Value'>𝕩</span><span class='Brace'>}</span></code></td>
+<td><code><span class='Function'>F</span><span class='Modifier2'>∘</span><span class='Function'>⊣</span> <span class='Function'>G</span> <span class='Function'>⊢</span></code></td>
+</tr>
+<tr>
+<td>After</td>
+<td><code><span class='Function'>F</span><span class='Modifier2'>⟜</span><span class='Function'>G</span></code></td>
+<td><code><span class='Value'>𝕩</span> <span class='Function'>F</span> <span class='Paren'>(</span><span class='Function'>G</span><span class='Value'>𝕩</span><span class='Paren'>)</span></code></td>
+<td><code><span class='Value'>𝕨</span> <span class='Function'>F</span> <span class='Paren'>(</span><span class='Function'>G</span><span class='Value'>𝕩</span><span class='Paren'>)</span></code></td>
+<td><code><span class='Brace'>{</span><span class='Paren'>(</span><span class='Value'>𝕨</span><span class='Function'>⊣</span><span class='Value'>𝕩</span><span class='Paren'>)</span><span class='Function'>𝔽𝔾</span><span class='Value'>𝕩</span><span class='Brace'>}</span></code></td>
+<td><code><span class='Function'>⊣</span> <span class='Function'>F</span> <span class='Function'>G</span><span class='Modifier2'>∘</span><span class='Function'>⊢</span></code></td>
+</tr>
+</tbody>
+</table>
+<h2 id="description"><a class="header" href="#description">Description</a></h2>
+<p>In the general case, I think of Before as using <code><span class='Function'>𝔽</span></code> as a preprocessing function applied to <code><span class='Value'>𝕨</span></code> (when there are two arguments) and After as using <code><span class='Function'>𝔾</span></code> as preprocessing for <code><span class='Value'>𝕩</span></code>. Then the other operand is called on the result and remaining argument. Here are some simple calls with Pair (<code><span class='Function'>⋈</span></code>): the result is a pair that corresponds to <code><span class='Value'>𝕨</span><span class='Ligature'>‿</span><span class='Value'>𝕩</span></code>, but one or the other result has been modified by the pointy-side function.</p>
+<a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=OSDiiJriirjii4ggMgoKOSDii4jin5zihpUgMg==">↗️</a><pre>    <span class='Number'>9</span> <span class='Function'>√</span><span class='Modifier2'>⊸</span><span class='Function'>⋈</span> <span class='Number'>2</span>
+⟨ 3 2 ⟩
+
+    <span class='Number'>9</span> <span class='Function'>⋈</span><span class='Modifier2'>⟜</span><span class='Function'>↕</span> <span class='Number'>2</span>
+⟨ 9 ⟨ 0 1 ⟩ ⟩
+</pre>
+<p>When only one argument is given, it's used in both positions, so that the arguments to the final function are <code><span class='Value'>𝕩</span></code> and a function applied to <code><span class='Value'>𝕩</span></code>.</p>
+<a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=4ouI4p+c4oaVIDU=">↗️</a><pre>    <span class='Function'>⋈</span><span class='Modifier2'>⟜</span><span class='Function'>↕</span> <span class='Number'>5</span>
+⟨ 5 ⟨ 0 1 2 3 4 ⟩ ⟩
+</pre>
+<p>This can be used to make a &quot;filter&quot; pattern using <a href="replicate.html">Replicate</a> (<code><span class='Function'>/</span></code>). The difference is that Replicate takes a list <code><span class='Value'>𝕩</span></code> and boolean list <code><span class='Value'>𝕨</span></code> indicating which elements to keep, but filter should take a list and a function that says whether to keep each element. The pattern is <code><span class='Function'>F</span><span class='Modifier'>¨</span><span class='Modifier2'>⊸</span><span class='Function'>/</span> <span class='Value'>x</span></code>, expanding to <code><span class='Paren'>(</span><span class='Function'>F</span><span class='Modifier'>¨</span><span class='Value'>x</span><span class='Paren'>)</span> <span class='Function'>/</span> <span class='Value'>x</span></code>. Here's a list filtered with the function <code><span class='Brace'>{</span><span class='Value'>𝕩</span><span class='Function'>&lt;</span><span class='Number'>0</span><span class='Brace'>}</span></code>.</p>
+<a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=e/Cdlak8MH3CqOKKuC8gNOKAv8KvMuKAvzHigL/CrzPigL/CrzM=">↗️</a><pre>    <span class='Brace'>{</span><span class='Value'>𝕩</span><span class='Function'>&lt;</span><span class='Number'>0</span><span class='Brace'>}</span><span class='Modifier'>¨</span><span class='Modifier2'>⊸</span><span class='Function'>/</span> <span class='Number'>4</span><span class='Ligature'>‿</span><span class='Number'>¯2</span><span class='Ligature'>‿</span><span class='Number'>1</span><span class='Ligature'>‿</span><span class='Number'>¯3</span><span class='Ligature'>‿</span><span class='Number'>¯3</span>
+⟨ ¯2 ¯3 ¯3 ⟩
+</pre>
+<p>As <code><span class='Function'>&lt;</span></code> is a pervasive function, there's no need for the Each (<code><span class='Modifier'>¨</span></code>) in this case, and the clunky block function <code><span class='Brace'>{</span><span class='Value'>𝕩</span><span class='Function'>&lt;</span><span class='Number'>0</span><span class='Brace'>}</span></code> can also be written smaller with a combinator, as <code><span class='Function'>&lt;</span><span class='Modifier2'>⟜</span><span class='Number'>0</span></code>. More on that in the next section…</p>
+<a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=POKfnDDiirgvIDTigL/CrzLigL8x4oC/wq8z4oC/wq8z">↗️</a><pre>    <span class='Function'>&lt;</span><span class='Modifier2'>⟜</span><span class='Number'>0</span><span class='Modifier2'>⊸</span><span class='Function'>/</span> <span class='Number'>4</span><span class='Ligature'>‿</span><span class='Number'>¯2</span><span class='Ligature'>‿</span><span class='Number'>1</span><span class='Ligature'>‿</span><span class='Number'>¯3</span><span class='Ligature'>‿</span><span class='Number'>¯3</span>
+⟨ ¯2 ¯3 ¯3 ⟩
+</pre>
+<h2 id="bind"><a class="header" href="#bind">Bind</a></h2>
+<p>&quot;Bind&quot; isn't a special case of Before and After, but instead a description of one way to use them. Let's take a look at the example from the previous section:</p>
+<a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=POKfnDAgIDTigL/CrzLigL8x4oC/wq8z4oC/wq8z">↗️</a><pre>    <span class='Function'>&lt;</span><span class='Modifier2'>⟜</span><span class='Number'>0</span>  <span class='Number'>4</span><span class='Ligature'>‿</span><span class='Number'>¯2</span><span class='Ligature'>‿</span><span class='Number'>1</span><span class='Ligature'>‿</span><span class='Number'>¯3</span><span class='Ligature'>‿</span><span class='Number'>¯3</span>
+⟨ 0 1 0 1 1 ⟩
+</pre>
+<p>If we expand <code><span class='Function'>&lt;</span><span class='Modifier2'>⟜</span><span class='Number'>0</span> <span class='Value'>x</span></code>, we get <code><span class='Value'>x</span> <span class='Function'>&lt;</span> <span class='Paren'>(</span><span class='Number'>0</span> <span class='Value'>x</span><span class='Paren'>)</span></code>, which doesn't quite make sense. That's because <code><span class='Number'>0</span></code> has a subject role, but <code><span class='Modifier2'>⟜</span></code> always applies its operands as functions. It's more accurate to use <code><span class='Value'>x</span> <span class='Function'>&lt;</span> <span class='Paren'>(</span><span class='Number'>0</span><span class='Brace'>{</span><span class='Function'>𝔽</span><span class='Brace'>}</span> <span class='Value'>x</span><span class='Paren'>)</span></code>, or just skip ahead to <code><span class='Value'>x</span> <span class='Function'>&lt;</span> <span class='Number'>0</span></code>.</p>
+<p>Similar reasoning gives the following expansions:</p>
+<table>
+<thead>
+<tr>
+<th><code><span class='Function'>Cmp</span></code></th>
+<th><code><span class='Number'>0</span><span class='Modifier2'>⊸</span><span class='Function'>&lt;</span></code></th>
+<th><code><span class='Function'>&lt;</span><span class='Modifier2'>⟜</span><span class='Number'>0</span></code></th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td><code>  <span class='Function'>Cmp</span> <span class='Value'>x</span></code></td>
+<td><code><span class='Number'>0</span> <span class='Function'>&lt;</span> <span class='Value'>x</span></code></td>
+<td><code><span class='Value'>x</span> <span class='Function'>&lt;</span> <span class='Number'>0</span></code></td>
+</tr>
+<tr>
+<td><code><span class='Value'>w</span> <span class='Function'>Cmp</span> <span class='Value'>x</span></code></td>
+<td><code><span class='Number'>0</span> <span class='Function'>&lt;</span> <span class='Value'>x</span></code></td>
+<td><code><span class='Value'>w</span> <span class='Function'>&lt;</span> <span class='Number'>0</span></code></td>
+</tr>
+</tbody>
+</table>
+<p>Note that when there are two arguments, the constant &quot;swallows&quot; the one on the same side, so that the function is applied to the constant and the argument on the <em>opposite</em> side.</p>
+<p>As in a train, if you want to use a function as a constant then you need to be explicity about it, with the <a href="constant.html">Constant</a> (<code><span class='Modifier'>˙</span></code>) modifier.</p>
+<a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=MyDii4jin5wo4oyKy5kp4oq44qWKICdhJyvihpUxMg==">↗️</a><pre>    <span class='Number'>3</span> <span class='Function'>⋈</span><span class='Modifier2'>⟜</span><span class='Paren'>(</span><span class='Function'>⌊</span><span class='Modifier'>˙</span><span class='Paren'>)</span><span class='Modifier2'>⊸</span><span class='Function'>⥊</span> <span class='String'>'a'</span><span class='Function'>+↕</span><span class='Number'>12</span>
+┌─      
+╵"abcd  
+  efgh  
+  ijkl" 
+       ┘
+</pre>
+<p>In the more extreme case of wanting a <em>modifier</em> operand, you might try <code><span class='Function'>⋈</span><span class='Modifier2'>⟜</span><span class='Paren'>(</span><span class='Brace'>{</span><span class='Modifier2'>∘</span><span class='Brace'>}</span><span class='Modifier'>˙</span><span class='Paren'>)</span><span class='Modifier2'>⊸</span><span class='Function'>⥊</span></code>, or <code><span class='Paren'>(</span><span class='Function'>⊣⋈</span><span class='Brace'>{</span><span class='Modifier2'>∘</span><span class='Brace'>}</span><span class='Modifier'>˙</span><span class='Paren'>)</span><span class='Modifier2'>⊸</span><span class='Function'>⥊</span></code>, or just cheat with <code><span class='Function'>∾</span><span class='Modifier2'>⟜</span><span class='Bracket'>⟨</span><span class='Modifier2'>∘</span><span class='Bracket'>⟩</span><span class='Modifier2'>⊸</span><span class='Function'>⥊</span></code>.</p>
diff --git a/docs/doc/index.html b/docs/doc/index.html
index 66bdbfec..82af1d4c 100644
--- a/docs/doc/index.html
+++ b/docs/doc/index.html
@@ -48,6 +48,7 @@
 <li><a href="shape.html">Array dimensions</a> (<code><span class='Function'>≢=≠</span></code>)</li>
 <li><a href="assert.html">Assert and Catch</a> (<code><span class='Function'>!</span></code> and <code><span class='Modifier2'>⎊</span></code>)</li>
 <li><a href="compose.html">Atop and Over</a> (<code><span class='Modifier2'>∘○</span></code>)</li>
+<li><a href="hook.html">Before and After</a> (<code><span class='Modifier2'>⊸⟜</span></code>)</li>
 <li><a href="choose.html">Choose</a> (<code><span class='Modifier2'>◶</span></code>)</li>
 <li><a href="constant.html">Constant</a> (<code><span class='Modifier'>˙</span></code>)</li>
 <li><a href="reshape.html">Deshape and Reshape</a> (<code><span class='Function'>⥊</span></code>)</li>
diff --git a/docs/doc/primitive.html b/docs/doc/primitive.html
index aa3fd087..fd153f5a 100644
--- a/docs/doc/primitive.html
+++ b/docs/doc/primitive.html
@@ -449,13 +449,13 @@
 </tr>
 <tr>
 <td><code><span class='Modifier2'>⊸</span></code></td>
-<td>Before/Bind</td>
+<td><a href="hook.html">Before/Bind</a></td>
 <td><code><span class='Brace'>{</span><span class='Paren'>(</span><span class='Function'>𝔽</span><span class='Value'>𝕨</span><span class='Function'>⊣</span><span class='Value'>𝕩</span><span class='Paren'>)</span><span class='Function'>𝔾</span><span class='Value'>𝕩</span><span class='Brace'>}</span></code></td>
 <td><code><span class='Function'>𝔾</span></code>'s left argument comes from <code><span class='Function'>𝔽</span></code></td>
 </tr>
 <tr>
 <td><code><span class='Modifier2'>⟜</span></code></td>
-<td>After/Bind</td>
+<td><a href="hook.html">After/Bind</a></td>
 <td><code><span class='Brace'>{</span><span class='Paren'>(</span><span class='Value'>𝕨</span><span class='Function'>⊣</span><span class='Value'>𝕩</span><span class='Paren'>)</span><span class='Function'>𝔽𝔾</span><span class='Value'>𝕩</span><span class='Brace'>}</span></code></td>
 <td><code><span class='Function'>𝔽</span></code>'s right argument comes from <code><span class='Function'>𝔾</span></code></td>
 </tr>
diff --git a/docs/help/after_bind.html b/docs/help/after_bind.html
index 8ef227af..490f105e 100644
--- a/docs/help/after_bind.html
+++ b/docs/help/after_bind.html
@@ -6,6 +6,7 @@
 <div class="nav">(<a href="https://github.com/mlochbaum/BQN">github</a>) / <a href="../index.html">BQN</a> / <a href="index.html">help</a></div>
 <h1 id="left-multimap-"><a class="header" href="#left-multimap-">Left Multimap (<code><span class='Modifier2'>⟜</span></code>)</a></h1>
 <h2 id="𝔽𝕘-𝕩-bind"><a class="header" href="#𝔽𝕘-𝕩-bind"><code><span class='Function'>𝔽</span><span class='Modifier2'>⟜</span><span class='Value'>𝕘</span> <span class='Value'>𝕩</span></code>: Bind</a></h2>
+<p><a class="fulldoc" href="../doc/hook.html#bind">→full documentation</a></p>
 <p>Supply <code><span class='Value'>𝕘</span></code> as a right argument to <code><span class='Function'>𝔽</span></code> (<code><span class='Value'>𝕩</span> <span class='Function'>𝔽</span> <span class='Value'>𝕘</span></code>).</p>
 <p><code><span class='Value'>𝕘</span></code> is a constant, <code><span class='Function'>𝔽</span></code> must be dyadic.</p>
 <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=LeKfnDMgOQoKLSAzIDkKCjkgLSAz">↗️</a><pre>    <span class='Function'>-</span><span class='Modifier2'>⟜</span><span class='Number'>3</span> <span class='Number'>9</span>
@@ -18,6 +19,7 @@
 6
 </pre>
 <h2 id="𝔽𝔾-𝕩-after"><a class="header" href="#𝔽𝔾-𝕩-after"><code><span class='Function'>𝔽</span><span class='Modifier2'>⟜</span><span class='Function'>𝔾</span> <span class='Value'>𝕩</span></code>: After</a></h2>
+<p><a class="fulldoc" href="../doc/hook.html">→full documentation</a></p>
 <p>Apply <code><span class='Function'>𝔾</span></code> to <code><span class='Value'>𝕩</span></code>, and supply it as a right argument to <code><span class='Function'>𝔽</span></code> (<code><span class='Value'>𝕩</span> <span class='Function'>𝔽</span> <span class='Paren'>(</span><span class='Function'>𝔾</span> <span class='Value'>𝕩</span><span class='Paren'>)</span></code>).</p>
 <p><code><span class='Function'>𝔽</span></code> must be dyadic, <code><span class='Function'>𝔾</span></code> must be monadic.</p>
 <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=w5fin5wtIDkKCsOXIC0gOQoKOSDDlyAoLSA5KQ==">↗️</a><pre>    <span class='Function'>×</span><span class='Modifier2'>⟜</span><span class='Function'>-</span> <span class='Number'>9</span>
@@ -30,6 +32,7 @@
 ¯81
 </pre>
 <h2 id="𝕨-𝔽𝔾-𝕩-dyadic-after"><a class="header" href="#𝕨-𝔽𝔾-𝕩-dyadic-after"><code><span class='Value'>𝕨</span> <span class='Function'>𝔽</span><span class='Modifier2'>⟜</span><span class='Function'>𝔾</span> <span class='Value'>𝕩</span></code>: Dyadic After</a></h2>
+<p><a class="fulldoc" href="../doc/hook.html">→full documentation</a></p>
 <p>Apply <code><span class='Function'>𝔾</span></code> to <code><span class='Value'>𝕩</span></code>, and supply it as a right argument to <code><span class='Function'>𝔽</span></code> (<code><span class='Value'>𝕨</span> <span class='Function'>𝔽</span> <span class='Paren'>(</span><span class='Function'>𝔾</span> <span class='Value'>𝕩</span><span class='Paren'>)</span></code>).</p>
 <p><code><span class='Function'>𝔽</span></code> must be dyadic, <code><span class='Function'>𝔾</span></code> must be monadic.</p>
 <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=MiDDl+KfnC0gMQoKMiDDlyAoLSAxKQ==">↗️</a><pre>    <span class='Number'>2</span> <span class='Function'>×</span><span class='Modifier2'>⟜</span><span class='Function'>-</span> <span class='Number'>1</span>
diff --git a/docs/help/before_bind.html b/docs/help/before_bind.html
index c9f0ca0b..d240921b 100644
--- a/docs/help/before_bind.html
+++ b/docs/help/before_bind.html
@@ -6,6 +6,7 @@
 <div class="nav">(<a href="https://github.com/mlochbaum/BQN">github</a>) / <a href="../index.html">BQN</a> / <a href="index.html">help</a></div>
 <h1 id="multimap-"><a class="header" href="#multimap-">Multimap (<code><span class='Modifier2'>⊸</span></code>)</a></h1>
 <h2 id="𝕗𝔾-𝕩-bind-left"><a class="header" href="#𝕗𝔾-𝕩-bind-left"><code><span class='Value'>𝕗</span><span class='Modifier2'>⊸</span><span class='Function'>𝔾</span> <span class='Value'>𝕩</span></code>: Bind Left</a></h2>
+<p><a class="fulldoc" href="../doc/hook.html#bind">→full documentation</a></p>
 <p>Supply <code><span class='Value'>𝕗</span></code> as a left argument to <code><span class='Function'>𝔾</span></code> (<code><span class='Value'>𝕗</span> <span class='Function'>𝔾</span> <span class='Value'>𝕩</span></code>).</p>
 <p><code><span class='Value'>𝕗</span></code> is a constant, <code><span class='Function'>𝔾</span></code> must be dyadic.</p>
 <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=M+KKuC0gOQoKMyAtIDk=">↗️</a><pre>    <span class='Number'>3</span><span class='Modifier2'>⊸</span><span class='Function'>-</span> <span class='Number'>9</span>
@@ -15,6 +16,7 @@
 ¯6
 </pre>
 <h2 id="𝔽𝔾-𝕩-before"><a class="header" href="#𝔽𝔾-𝕩-before"><code><span class='Function'>𝔽</span><span class='Modifier2'>⊸</span><span class='Function'>𝔾</span> <span class='Value'>𝕩</span></code>: Before</a></h2>
+<p><a class="fulldoc" href="../doc/hook.html">→full documentation</a></p>
 <p>Apply <code><span class='Function'>𝔽</span></code> to <code><span class='Value'>𝕩</span></code>, and supply it as a left argument to <code><span class='Function'>𝔾</span></code> (<code><span class='Paren'>(</span><span class='Function'>𝔽</span> <span class='Value'>𝕩</span><span class='Paren'>)</span> <span class='Function'>𝔾</span> <span class='Value'>𝕩</span></code>).</p>
 <p><code><span class='Function'>𝔽</span></code> must be monadic, <code><span class='Function'>𝔾</span></code> must be dyadic.</p>
 <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=LeKKuCsgOQoKLSArIDkKCigtIDkpICsgOQ==">↗️</a><pre>    <span class='Function'>-</span><span class='Modifier2'>⊸</span><span class='Function'>+</span> <span class='Number'>9</span>
@@ -27,6 +29,7 @@
 0
 </pre>
 <h2 id="𝕨-𝔽𝔾-𝕩-dyadic-before"><a class="header" href="#𝕨-𝔽𝔾-𝕩-dyadic-before"><code><span class='Value'>𝕨</span> <span class='Function'>𝔽</span><span class='Modifier2'>⊸</span><span class='Function'>𝔾</span> <span class='Value'>𝕩</span></code>: Dyadic Before</a></h2>
+<p><a class="fulldoc" href="../doc/hook.html">→full documentation</a></p>
 <p>Apply <code><span class='Function'>𝔽</span></code> to <code><span class='Value'>𝕨</span></code>, and supply it as a left argument to <code><span class='Function'>𝔾</span></code> (<code><span class='Paren'>(</span><span class='Function'>𝔽</span> <span class='Value'>𝕨</span><span class='Paren'>)</span> <span class='Function'>𝔾</span> <span class='Value'>𝕩</span></code>).</p>
 <p><code><span class='Function'>𝔽</span></code> must be monadic, <code><span class='Function'>𝔾</span></code> must be dyadic.</p>
 <a class="replLink" title="Open in the REPL" target="_blank" href="https://mlochbaum.github.io/BQN/try.html#code=MiAt4oq4KyAxCgoyIC0gKyAxCgooLSAyKSArIDE=">↗️</a><pre>    <span class='Number'>2</span> <span class='Function'>-</span><span class='Modifier2'>⊸</span><span class='Function'>+</span> <span class='Number'>1</span>