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add hack-a-round for language specified markdown code blocks

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When language is specified in a markdown code block such as:

````
```c
    printf("Hello, world!\n");
```
````

is used, the resulting HTML as produced by `pandoc(1)` combined
with our revised `ioccc.css` is not intent the code block well.

A temporary "_hack-a-round_" is to turn the "markdown code language
specifier" into an HTML comment.  For example:

````
```<!---c-->
    printf("Hello, world!\n");
```
````

This commits turns off existing markdown code language specifiers
for now, while preserving our ability to restore them in the future
when a better  "_hack-a-round_" to the "markdown code language
specifier" problem is found.

The HTML impact if this "_hack-a-round_" is to produce HTML that
looks like this:

```
<pre class="&lt;!---c--&gt;"><code> .. </code></pre>
```

We might be able to create a complex set of classes for each markdown
code language (there won't be very many) in `ioccc.css`, or we might
find a more general CSS (or maybe `pandoc(1)`?) solution.

For now, this hack-a-round will have to do.
This commit is contained in:
Landon Curt Noll committed 2024-04-04 14:50:38 -07:00
1 parent 3919df50fb
commit b66c79254a
700 files changed
+7052 -7056
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2012/tromp/index.html
+97 -97
View File
@@ -141,21 +141,21 @@ Location: <a href="../../location.html#US">US</a> - <em>United States of America
<!-- START: this line starts content for HTML phase 21 by: bin/pandoc-wrapper.sh via bin/md2html.sh -->
<h2 id="to-build">To build:</h2>
<div class="sourceCode" id="cb1"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a> <span class="fu">make</span> all <span class="co"># On a 64-bit machine (default)</span></span>
<span id="cb1-2"><a href="#cb1-2" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb1-3"><a href="#cb1-3" aria-hidden="true" tabindex="-1"></a> <span class="fu">make</span> tromp32 <span class="co"># On a 32-bit machine</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> make all # On a 64-bit machine (default)
make tromp32 # On a 32-bit machine</code></pre>
<h3 id="bugs-and-misfeatures">Bugs and (Mis)features:</h3>
<p>The current status of this entry is:</p>
<pre><code> STATUS: INABIAF - please **DO NOT** fix</code></pre>
<p>For more detailed information see <a href="../../bugs.html#2012_tromp">2012 tromp bugs</a>.</p>
<h2 id="to-use">To use:</h2>
<div class="sourceCode" id="cb3"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">./tromp</span> <span class="pp">[-</span><span class="ss">b</span><span class="pp">]</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> ./tromp [-b]</code></pre>
<p>Use <code>./tromp32</code> as you would <code>./tromp</code> if on a 32-bit machine.</p>
<h2 id="to-use-1">To use:</h2>
<div class="sourceCode" id="cb4"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb4-1"><a href="#cb4-1" aria-hidden="true" tabindex="-1"></a> <span class="fu">cat</span> ascii-prog.blc data <span class="kw">|</span> <span class="ex">./tromp</span> <span class="at">-b</span></span>
<span id="cb4-2"><a href="#cb4-2" aria-hidden="true" tabindex="-1"></a> <span class="fu">cat</span> binary-prog.Blc data <span class="kw">|</span> <span class="ex">./tromp</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> cat ascii-prog.blc data | ./tromp -b
cat binary-prog.Blc data | ./tromp</code></pre>
<h2 id="try">Try:</h2>
<div class="sourceCode" id="cb5"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">./try.sh</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> ./try.sh</code></pre>
<h2 id="judges-remarks">Judges’ remarks:</h2>
<p>The judges dare to say that the data files this entry is processing
are more obfuscated than the entry itself.</p>
@@ -206,23 +206,23 @@ notation</a>) which is the
identity function. When its encoding <code>0010</code> is fed into the universal machine,
it will simply copy the input to the output (well, not that simply, since each
byte is smashed to bits and rebuilt from scratch). Voila: a half byte cat:</p>
<div class="sourceCode" id="cb7"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> echo <span class="st">&quot; Hello, world&quot;</span> <span class="kw">|</span> <span class="ex">./tromp</span></span>
<span id="cb7-2"><a href="#cb7-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">Hello,</span> world</span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> $ echo &quot; Hello, world&quot; | ./tromp
Hello, world</code></pre>
<p>Since the least significant 4 bits of the first byte are just arbitrary padding
that is ignored by the program, any character from ASCII 32 (space) through 47
(<code>/</code>) will do, e.g.:</p>
<div class="sourceCode" id="cb8"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> echo <span class="st">&quot;*Hello, world&quot;</span> <span class="kw">|</span> <span class="ex">./tromp</span></span>
<span id="cb8-2"><a href="#cb8-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">Hello,</span> world</span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> $ echo &quot;*Hello, world&quot; | ./tromp
Hello, world</code></pre>
<h3 id="bad-programs">Bad programs</h3>
<p>If the input doesn’t start with a valid program, that is,
if the interpreter reaches end-of-file during program parsing,
it will crash in some way. E.g. the following might dump core:</p>
<div class="sourceCode" id="cb9"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" aria-hidden="true" tabindex="-1"></a> <span class="bu">echo</span> <span class="at">-n</span> <span class="st">&quot;U&quot;</span> <span class="kw">|</span> <span class="ex">./tromp</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> echo -n &quot;U&quot; | ./tromp</code></pre>
<p>Furthermore, the interpreter requires the initial encoded lambda term to be
closed, that is, variable <code>n</code> can only appear within at least <code>n</code> enclosing
lambdas. For instance, here the term <code>\ 5</code> is not closed, causing the
interpreter to crash when looking into a null-pointer environment:</p>
<div class="sourceCode" id="cb10"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb10-1"><a href="#cb10-1" aria-hidden="true" tabindex="-1"></a> <span class="bu">echo</span> <span class="st">&quot;&gt;Hello, world&quot;</span> <span class="kw">|</span> <span class="ex">./tromp</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> echo &quot;&gt;Hello, world&quot; | ./tromp</code></pre>
<p>will likely dump core.</p>
<p>Since these properties can be checked when creating
<a href="https://tromp.github.io/cl/Binary_lambda_calculus.html">BLC</a> programs,
@@ -265,8 +265,8 @@ as a self interpreter in BLC it is downright minuscule at 232 bits (29 bytes):</
0b7fb 00cf6
7bb03 91a1a
</code></pre>
<div class="sourceCode" id="cb13"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> <span class="er">(</span><span class="fu">cat</span> uni8.Blc<span class="kw">;</span> <span class="bu">echo</span> <span class="st">&quot; Ni hao&quot;</span><span class="kw">)</span> <span class="kw">|</span> <span class="ex">./tromp</span></span>
<span id="cb13-2"><a href="#cb13-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">Ni</span> hao</span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> $ (cat uni8.Blc; echo &quot; Ni hao&quot;) | ./tromp
Ni hao</code></pre>
<h3 id="a-prime-number-sieve">A prime number sieve</h3>
<p>Even shorter than the self-interpreter is this prime number sieve in 167 bits
(under 21 bytes):</p>
@@ -281,8 +281,8 @@ as a self interpreter in BLC it is downright minuscule at 232 bits (29 bytes):</
0000110110
</code></pre>
<p>The <code>n</code>th bit in the output indicates whether n is prime:</p>
<div class="sourceCode" id="cb15"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> cat primes.blc <span class="kw">|</span> <span class="ex">./tromp</span> <span class="at">-b</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-c</span> 70</span>
<span id="cb15-2"><a href="#cb15-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">0011010100010100010100010000010100000100010100010000010000010100000100</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> $ cat primes.blc | ./tromp -b | head -c 70
0011010100010100010100010000010100000100010100010000010000010100000100</code></pre>
<p>For those who prefer to digest their primes in decimal, there is <code>oddindices.Blc</code>,
which will print the indices of all odd characters (with
<a href="https://en.wikipedia.org/wiki/Bit_numbering">LSB</a> = 1)
@@ -308,43 +308,43 @@ separated by a given character:</p>
60 8191a00167fb cbcfdf65f7c0 a20</code></pre>
<p>It expects <code>n</code> arbitrary characters of input, and draws a space filling <a href="https://en.wikipedia.org/wiki/Hilbert_curve">Hilbert
curve</a> of order <code>n</code>:</p>
<div class="sourceCode" id="cb18"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> <span class="er">(</span><span class="fu">cat</span> hilbert.Blc<span class="kw">;</span> <span class="bu">echo</span> <span class="at">-n</span> <span class="st">&quot;1&quot;</span><span class="kw">)</span> <span class="kw">|</span> <span class="ex">./tromp</span></span>
<span id="cb18-2"><a href="#cb18-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span></span>
<span id="cb18-3"><a href="#cb18-3" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span> <span class="kw">|</span></span>
<span id="cb18-4"><a href="#cb18-4" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb18-5"><a href="#cb18-5" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> <span class="er">(</span><span class="fu">cat</span> hilbert.Blc<span class="kw">;</span> <span class="bu">echo</span> <span class="at">-n</span> <span class="st">&quot;12&quot;</span><span class="kw">)</span> <span class="kw">|</span> <span class="ex">./tromp</span></span>
<span id="cb18-6"><a href="#cb18-6" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span> _</span>
<span id="cb18-7"><a href="#cb18-7" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span></span>
<span id="cb18-8"><a href="#cb18-8" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span></span>
<span id="cb18-9"><a href="#cb18-9" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span></span>
<span id="cb18-10"><a href="#cb18-10" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb18-11"><a href="#cb18-11" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> <span class="er">(</span><span class="fu">cat</span> hilbert.Blc<span class="kw">;</span> <span class="bu">echo</span> <span class="at">-n</span> <span class="st">&quot;123&quot;</span><span class="kw">)</span> <span class="kw">|</span> <span class="ex">./tromp</span></span>
<span id="cb18-12"><a href="#cb18-12" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span> _ _ _</span>
<span id="cb18-13"><a href="#cb18-13" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span></span>
<span id="cb18-14"><a href="#cb18-14" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span></span>
<span id="cb18-15"><a href="#cb18-15" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_____</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span></span>
<span id="cb18-16"><a href="#cb18-16" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span> <span class="ex">___</span> ___ <span class="kw">|</span></span>
<span id="cb18-17"><a href="#cb18-17" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span></span>
<span id="cb18-18"><a href="#cb18-18" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span> <span class="ex">_</span></span>
<span id="cb18-19"><a href="#cb18-19" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span></span>
<span id="cb18-20"><a href="#cb18-20" aria-hidden="true" tabindex="-1"></a></span>
<span id="cb18-21"><a href="#cb18-21" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> <span class="er">(</span><span class="fu">cat</span> hilbert.Blc<span class="kw">;</span> <span class="bu">echo</span> <span class="at">-n</span> <span class="st">&quot;1234&quot;</span><span class="kw">)</span> <span class="kw">|</span> <span class="ex">./tromp</span></span>
<span id="cb18-22"><a href="#cb18-22" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span> _ _ _ _ _ _ _</span>
<span id="cb18-23"><a href="#cb18-23" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span></span>
<span id="cb18-24"><a href="#cb18-24" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span></span>
<span id="cb18-25"><a href="#cb18-25" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_____</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span> <span class="kw">|</span><span class="ex">_____</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span></span>
<span id="cb18-26"><a href="#cb18-26" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span> <span class="ex">___</span> ___ <span class="kw">|</span> <span class="kw">|</span> <span class="ex">___</span> ___ <span class="kw">|</span></span>
<span id="cb18-27"><a href="#cb18-27" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span></span>
<span id="cb18-28"><a href="#cb18-28" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span> <span class="ex">_</span> _ <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span> <span class="ex">_</span></span>
<span id="cb18-29"><a href="#cb18-29" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span></span>
<span id="cb18-30"><a href="#cb18-30" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span><span class="ex">_</span> ___ ___ ___ ___ _<span class="kw">|</span></span>
<span id="cb18-31"><a href="#cb18-31" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span></span>
<span id="cb18-32"><a href="#cb18-32" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span> <span class="ex">_</span> <span class="kw">|</span> <span class="ex">_</span> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span> <span class="ex">_</span> <span class="kw">|</span> <span class="ex">_</span> <span class="kw">|</span></span>
<span id="cb18-33"><a href="#cb18-33" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span></span>
<span id="cb18-34"><a href="#cb18-34" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span> _ <span class="kw">|</span> <span class="ex">___</span> ___ <span class="kw">|</span> <span class="ex">_</span> _</span>
<span id="cb18-35"><a href="#cb18-35" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span></span>
<span id="cb18-36"><a href="#cb18-36" aria-hidden="true" tabindex="-1"></a> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span> <span class="ex">_</span> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span> <span class="ex">_</span> <span class="kw">|</span><span class="ex">_</span> _<span class="kw">|</span></span>
<span id="cb18-37"><a href="#cb18-37" aria-hidden="true" tabindex="-1"></a> <span class="ex">_</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">___</span><span class="kw">|</span> <span class="kw">|</span><span class="ex">_</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> $ (cat hilbert.Blc; echo -n &quot;1&quot;) | ./tromp
_
| |
$ (cat hilbert.Blc; echo -n &quot;12&quot;) | ./tromp
_ _
| |_| |
|_ _|
_| |_
$ (cat hilbert.Blc; echo -n &quot;123&quot;) | ./tromp
_ _ _ _
| |_| | | |_| |
|_ _| |_ _|
_| |_____| |_
| ___ ___ |
|_| _| |_ |_|
_ |_ _| _
| |___| |___| |
$ (cat hilbert.Blc; echo -n &quot;1234&quot;) | ./tromp
_ _ _ _ _ _ _ _
| |_| | | |_| | | |_| | | |_| |
|_ _| |_ _| |_ _| |_ _|
_| |_____| |_ _| |_____| |_
| ___ ___ | | ___ ___ |
|_| _| |_ |_| |_| _| |_ |_|
_ |_ _| _ _ |_ _| _
| |___| |___| |_| |___| |___| |
|_ ___ ___ ___ ___ _|
_| |_ |_| _| |_ |_| _| |_
| _ | _ |_ _| _ | _ |
|_| |_| | |___| |___| | |_| |_|
_ _ | ___ ___ | _ _
| |_| | |_| _| |_ |_| | |_| |
|_ _| _ |_ _| _ |_ _|
_| |___| |___| |___| |___| |_</code></pre>
<h3 id="a-brainfuck-interpreter">A <a href="https://en.wikipedia.org/wiki/Brainfuck">Brainfuck</a> interpreter</h3>
<p>The smallest known BF interpreter is written in… you guessed it,
<a href="https://tromp.github.io/cl/Binary_lambda_calculus.html">BLC</a>,
@@ -370,56 +370,56 @@ followed by a <code>]</code>, followed by the input for the Brainfuck program.</
<h3 id="a-blc-assembler">A BLC assembler</h3>
<p>Writing BLC programs can be made slightly less painful with this parser that
translates single-letter-variable lambda calculus into BLC:</p>
<div class="sourceCode" id="cb21"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> echo <span class="st">&quot;\f\x f (f (f x))&quot;</span> <span class="op">&gt;</span> three</span>
<span id="cb21-2"><a href="#cb21-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> cat parse.Blc three <span class="kw">|</span> <span class="ex">./tromp</span></span>
<span id="cb21-3"><a href="#cb21-3" aria-hidden="true" tabindex="-1"></a> <span class="ex">000001110011100111010</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> $ echo &quot;\f\x f (f (f x))&quot; &gt; three
$ cat parse.Blc three | ./tromp
000001110011100111010</code></pre>
<h3 id="converting-between-bits-and-bytes">Converting between bits and bytes</h3>
<p>The program <code>inflate.Blc</code> and its inverse <code>deflate.Blc</code> allow us to translate between
BLC and BLC8. If you assemble a byte oriented program, you’ll need to compact it
into BLC8:</p>
<p>So we could assemble an input reversing program as</p>
<div class="sourceCode" id="cb22"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" aria-hidden="true" tabindex="-1"></a> <span class="bu">echo</span> <span class="st">&quot;\a a ((\b b b) (\b \c \d \e d (b b) (\f f c e))) (\b \c c)&quot;</span> <span class="op">&gt;</span> reverse</span>
<span id="cb22-2"><a href="#cb22-2" aria-hidden="true" tabindex="-1"></a> <span class="fu">cat</span> parse.Blc reverse <span class="kw">|</span> <span class="ex">./tromp</span> <span class="op">&gt;</span> reverse.blc</span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> echo &quot;\a a ((\b b b) (\b \c \d \e d (b b) (\f f c e))) (\b \c c)&quot; &gt; reverse
cat parse.Blc reverse | ./tromp &gt; reverse.blc</code></pre>
<p>and change it to BLC8 with</p>
<div class="sourceCode" id="cb23"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> cat deflate.Blc reverse.blc <span class="kw">|</span> <span class="ex">./tromp</span> <span class="op">&gt;</span> rev.Blc</span>
<span id="cb23-2"><a href="#cb23-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> wc rev.Blc</span>
<span id="cb23-3"><a href="#cb23-3" aria-hidden="true" tabindex="-1"></a> <span class="ex">0</span> 1 9 rev.Blc</span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> $ cat deflate.Blc reverse.blc | ./tromp &gt; rev.Blc
$ wc rev.Blc
0 1 9 rev.Blc</code></pre>
<p>and then try it out with:</p>
<div class="sourceCode" id="cb24"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> cat rev.Blc <span class="at">-</span> <span class="kw">|</span> <span class="ex">./tromp</span></span>
<span id="cb24-2"><a href="#cb24-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">Hello,</span> world!</span>
<span id="cb24-3"><a href="#cb24-3" aria-hidden="true" tabindex="-1"></a> <span class="ex">^D</span></span>
<span id="cb24-4"><a href="#cb24-4" aria-hidden="true" tabindex="-1"></a> <span class="ex">!dlrow</span> ,olleH</span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> $ cat rev.Blc - | ./tromp
Hello, world!
^D
!dlrow ,olleH</code></pre>
<h3 id="symbolic-lambda-calculus-reduction">Symbolic Lambda Calculus reduction</h3>
<p>BLC8 program <code>symbolic.Blc</code> shows individual reduction steps on symbolic lambda terms.
Here it is used to show the calculation of 2^3 in Church numerals:</p>
<div class="sourceCode" id="cb25"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> echo <span class="st">&quot;(\f\x f (f (f x))) (\f\x f (f x))&quot;</span> <span class="op">&gt;</span> threetwo</span>
<span id="cb25-2"><a href="#cb25-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> cat parse.Blc threetwo <span class="kw">|</span> <span class="ex">./tromp</span> <span class="op">&gt;</span> threetwo.blc</span>
<span id="cb25-3"><a href="#cb25-3" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> cat symbolic.Blc threetwo.blc <span class="kw">|</span> <span class="ex">./tromp</span></span>
<span id="cb25-4"><a href="#cb25-4" aria-hidden="true" tabindex="-1"></a> <span class="kw">(</span><span class="ex">\a</span> <span class="dt">\b</span> a <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> b<span class="kw">)))</span> <span class="kw">(</span><span class="ex">\a</span> <span class="dt">\b</span> a <span class="er">(</span><span class="ex">a</span> b<span class="kw">))</span></span>
<span id="cb25-5"><a href="#cb25-5" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="er">(</span><span class="ex">\b</span> <span class="dt">\c</span> b <span class="er">(</span><span class="ex">b</span> c<span class="kw">))</span> <span class="kw">((</span><span class="ex">\b</span> <span class="dt">\c</span> b <span class="er">(</span><span class="ex">b</span> c<span class="kw">))</span> <span class="kw">((</span><span class="ex">\b</span> <span class="dt">\c</span> b <span class="er">(</span><span class="ex">b</span> c<span class="kw">))</span> <span class="ex">a</span><span class="kw">))</span></span>
<span id="cb25-6"><a href="#cb25-6" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> <span class="er">(</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span><span class="kw">)</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span><span class="kw">)</span> <span class="ex">b</span><span class="kw">)</span></span>
<span id="cb25-7"><a href="#cb25-7" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> <span class="er">(</span><span class="ex">\c</span> <span class="er">(</span><span class="ex">\d</span> <span class="dt">\e</span> d <span class="er">(</span><span class="ex">d</span> e<span class="kw">))</span> <span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\d</span> <span class="dt">\e</span> d <span class="er">(</span><span class="ex">d</span> e<span class="kw">))</span> <span class="ex">a</span> c<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span><span class="kw">)</span> <span class="ex">b</span><span class="kw">)</span></span>
<span id="cb25-8"><a href="#cb25-8" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> <span class="er">(</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span><span class="kw">)</span> <span class="ex">b</span><span class="kw">))</span></span>
<span id="cb25-9"><a href="#cb25-9" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> <span class="er">(</span><span class="ex">\c</span> a <span class="er">(</span><span class="ex">a</span> c<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span><span class="kw">)</span> <span class="ex">b</span><span class="kw">))</span></span>
<span id="cb25-10"><a href="#cb25-10" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> a <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span><span class="kw">)</span> <span class="ex">b</span><span class="kw">)))</span></span>
<span id="cb25-11"><a href="#cb25-11" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> a <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> a <span class="er">(</span><span class="ex">a</span> c<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span><span class="kw">)</span> <span class="ex">b</span><span class="kw">)))</span></span>
<span id="cb25-12"><a href="#cb25-12" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> a <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span><span class="kw">)</span> <span class="ex">b</span><span class="kw">))))</span></span>
<span id="cb25-13"><a href="#cb25-13" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> a <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> <span class="er">(</span><span class="ex">\d</span> <span class="dt">\e</span> d <span class="er">(</span><span class="ex">d</span> e<span class="kw">))</span> <span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\d</span> <span class="dt">\e</span> d <span class="er">(</span><span class="ex">d</span> e<span class="kw">))</span> <span class="ex">a</span> c<span class="kw">))</span> <span class="ex">b</span><span class="kw">))))</span></span>
<span id="cb25-14"><a href="#cb25-14" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> a <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span> b<span class="kw">)))))</span></span>
<span id="cb25-15"><a href="#cb25-15" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> a <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> a <span class="er">(</span><span class="ex">a</span> c<span class="kw">))</span> <span class="kw">((</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span> b<span class="kw">)))))</span></span>
<span id="cb25-16"><a href="#cb25-16" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> a <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> <span class="dt">\d</span> c <span class="er">(</span><span class="ex">c</span> d<span class="kw">))</span> <span class="ex">a</span> b<span class="kw">))))))</span></span>
<span id="cb25-17"><a href="#cb25-17" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> a <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> a <span class="er">(</span><span class="ex">a</span> c<span class="kw">))</span> <span class="ex">b</span><span class="kw">))))))</span></span>
<span id="cb25-18"><a href="#cb25-18" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="dt">\b</span> a <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> <span class="er">(</span><span class="ex">a</span> b<span class="kw">)))))))</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> $ echo &quot;(\f\x f (f (f x))) (\f\x f (f x))&quot; &gt; threetwo
$ cat parse.Blc threetwo | ./tromp &gt; threetwo.blc
$ cat symbolic.Blc threetwo.blc | ./tromp
(\a \b a (a (a b))) (\a \b a (a b))
\a (\b \c b (b c)) ((\b \c b (b c)) ((\b \c b (b c)) a))
\a \b (\c \d c (c d)) ((\c \d c (c d)) a) ((\c \d c (c d)) ((\c \d c (c d)) a) b)
\a \b (\c (\d \e d (d e)) a ((\d \e d (d e)) a c)) ((\c \d c (c d)) ((\c \d c (c d)) a) b)
\a \b (\c \d c (c d)) a ((\c \d c (c d)) a ((\c \d c (c d)) ((\c \d c (c d)) a) b))
\a \b (\c a (a c)) ((\c \d c (c d)) a ((\c \d c (c d)) ((\c \d c (c d)) a) b))
\a \b a (a ((\c \d c (c d)) a ((\c \d c (c d)) ((\c \d c (c d)) a) b)))
\a \b a (a ((\c a (a c)) ((\c \d c (c d)) ((\c \d c (c d)) a) b)))
\a \b a (a (a (a ((\c \d c (c d)) ((\c \d c (c d)) a) b))))
\a \b a (a (a (a ((\c (\d \e d (d e)) a ((\d \e d (d e)) a c)) b))))
\a \b a (a (a (a ((\c \d c (c d)) a ((\c \d c (c d)) a b)))))
\a \b a (a (a (a ((\c a (a c)) ((\c \d c (c d)) a b)))))
\a \b a (a (a (a (a (a ((\c \d c (c d)) a b))))))
\a \b a (a (a (a (a (a ((\c a (a c)) b))))))
\a \b a (a (a (a (a (a (a (a b)))))))</code></pre>
<p>As expected, the resulting normal form is <a href="https://en.wikipedia.org/wiki/Church_encoding">Church
numeral</a> 8.</p>
<p>Taking only the first line of output gives us a sort of BLC disassembler, an
exact inverse of the above assembler. The prime number sieve disassembles as
follows:</p>
<div class="sourceCode" id="cb26"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> cat symbolic.Blc primes.blc <span class="kw">|</span> <span class="ex">./tromp</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-1</span></span>
<span id="cb26-2"><a href="#cb26-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">\a</span> <span class="er">(</span><span class="ex">\b</span> b <span class="er">(</span><span class="ex">b</span> <span class="er">(</span><span class="kw">(</span><span class="ex">\c</span> c c<span class="kw">)</span> <span class="kw">(</span><span class="ex">\c</span> <span class="dt">\d</span> <span class="dt">\e</span> e <span class="er">(</span><span class="ex">\f</span> <span class="dt">\g</span> g<span class="kw">)</span> <span class="kw">((</span><span class="ex">\f</span> c c f <span class="er">(</span><span class="kw">(</span><span class="ex">\g</span> g g<span class="kw">)</span> <span class="kw">(</span><span class="ex">\g</span> f <span class="er">(</span><span class="ex">g</span> g<span class="kw">))))</span> <span class="kw">(</span><span class="ex">\f</span> <span class="dt">\g</span> <span class="dt">\h</span> <span class="dt">\i</span> i g <span class="er">(</span><span class="ex">h</span> <span class="er">(</span><span class="ex">d</span> f<span class="kw">)))))</span> <span class="kw">(</span><span class="ex">\c</span> <span class="dt">\d</span> <span class="dt">\e</span> b <span class="er">(</span><span class="ex">e</span> c<span class="kw">)))))</span> <span class="kw">(</span><span class="ex">\b</span> <span class="dt">\c</span> c <span class="er">(</span><span class="ex">\d</span> <span class="dt">\e</span> d<span class="kw">)</span> <span class="ex">b</span><span class="kw">)</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> $ cat symbolic.Blc primes.blc | ./tromp | head -1
\a (\b b (b ((\c c c) (\c \d \e e (\f \g g) ((\f c c f ((\g g g) (\g f (g g)))) (\f \g \h \i i g (h (d f))))) (\c \d \e b (e c))))) (\b \c c (\d \e d) b)</code></pre>
<p>Hardly any less obfuscated…</p>
<p>The last line of</p>
<div class="sourceCode" id="cb27"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" aria-hidden="true" tabindex="-1"></a> <span class="fu">cat</span> symbolic.Blc primes.blc <span class="kw">|</span> <span class="ex">./tromp</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-16</span></span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> cat symbolic.Blc primes.blc | ./tromp | head -16</code></pre>
<p>starts out as</p>
<pre><code> \a \b b (\c \d c) (\c c (\d \e d) (\d d (\e \f f) (\e e (\f \g g) ((\f (\g \h \i</code></pre>
<p>The <code>\a</code> is for ignoring the rest of the input (to which the universal machine
@@ -444,16 +444,16 @@ Syntax</a> which relies on the highly optimized
Haskell runtime system for evaluation. Of course individual BLC programs running
under the interpreter perform much worse than that same program written in Haskell.</p>
<p>Our interpreter copes well with extra levels of interpretation:</p>
<div class="sourceCode" id="cb29"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> time cat primes.blc <span class="kw">|</span> <span class="ex">./tromp</span> <span class="at">-b</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-c</span> 210 <span class="op">&gt;</span> /dev/null</span>
<span id="cb29-2"><a href="#cb29-2" aria-hidden="true" tabindex="-1"></a> <span class="ex">real</span> 0m0.043s</span>
<span id="cb29-3"><a href="#cb29-3" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> time cat uni.blc primes.blc <span class="kw">|</span> <span class="ex">./tromp</span> <span class="at">-b</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-c</span> 210 <span class="op">&gt;</span> /dev/null</span>
<span id="cb29-4"><a href="#cb29-4" aria-hidden="true" tabindex="-1"></a> <span class="ex">real</span> 0m0.191s</span>
<span id="cb29-5"><a href="#cb29-5" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> time cat uni.blc uni.blc primes.blc <span class="kw">|</span> <span class="ex">./tromp</span> <span class="at">-b</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-c</span> 210 <span class="op">&gt;</span> /dev/null</span>
<span id="cb29-6"><a href="#cb29-6" aria-hidden="true" tabindex="-1"></a> <span class="ex">real</span> 0m1.919s</span>
<span id="cb29-7"><a href="#cb29-7" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> time cat uni.blc uni.blc uni.blc primes.blc <span class="kw">|</span> <span class="ex">./tromp</span> <span class="at">-b</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-c</span> 210 <span class="op">&gt;</span> /dev/null</span>
<span id="cb29-8"><a href="#cb29-8" aria-hidden="true" tabindex="-1"></a> <span class="ex">real</span> 0m23.514s</span>
<span id="cb29-9"><a href="#cb29-9" aria-hidden="true" tabindex="-1"></a> <span class="ex">$</span> time cat uni.blc uni.blc uni.blc uni.blc primes.blc <span class="kw">|</span> <span class="ex">./tromp</span> <span class="at">-b</span> <span class="kw">|</span> <span class="fu">head</span> <span class="at">-c</span> 210 <span class="op">&gt;</span> /dev/null</span>
<span id="cb29-10"><a href="#cb29-10" aria-hidden="true" tabindex="-1"></a> <span class="ex">real</span> 4m52.700s</span></code></pre></div>
<pre class="&lt;!---sh--&gt;"><code> $ time cat primes.blc | ./tromp -b | head -c 210 &gt; /dev/null
real 0m0.043s
$ time cat uni.blc primes.blc | ./tromp -b | head -c 210 &gt; /dev/null
real 0m0.191s
$ time cat uni.blc uni.blc primes.blc | ./tromp -b | head -c 210 &gt; /dev/null
real 0m1.919s
$ time cat uni.blc uni.blc uni.blc primes.blc | ./tromp -b | head -c 210 &gt; /dev/null
real 0m23.514s
$ time cat uni.blc uni.blc uni.blc uni.blc primes.blc | ./tromp -b | head -c 210 &gt; /dev/null
real 4m52.700s</code></pre>
<h3 id="obfuscation">Obfuscation</h3>
<p>Obfuscation is due entirely to conciseness. Some questions to ponder:</p>
<p>Which of the term space codes <code>0</code>, <code>1</code>, <code>2</code>, <code>3</code> serve multiple purposes?</p>