let body = document.body;
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body.querySelectorAll('[class]').forEach(e=>doc[e.classList[0]]=e);
let setcount = !doc.count ? (s=>s) : (s=>{
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let exp=0, explain;
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     ,[[0,1,0,32],[0,0,484,4],[0,0,571,3],[0,0,614,6],[0,0,717,3],[0,0,730,8],[0,0,954,3],[0,0,964,3],[0,0,980,4],[0,0,1031,3],[0,0,1056,4],[1,1,1153,2],[0,0,1183,3],[0,0,1197,30],[1,0,2082,5],[1,1,2094,2],[1,1,2126,2],[0,1,2156,4],[0,0,2346,15],[0,0,2645,5],[0,0,2727,3],[0,0,2778,3]]
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    }
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  explain(); // Clear
  setExplain = doc.doexplain.classList.toggle('selected')
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}

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    let c = keys[ev.key];
    if (c) return typeChar(ev.target, c, ev);
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    doc.kb.classList.add('backslash');
    ev.preventDefault();
  }
}
let typeChar = (t, c, ev) => {
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  let i = t.selectionStart;
  t.value = v.slice(0,i)+c+v.slice(t.selectionEnd);
  t.selectionStart = t.selectionEnd = i+c.length;
  return false;
}

let syncls={ v:"Value", f:"Function", m:"Modifier", d:"Modifier2", n:"Number", g:"Gets", p:"Paren", b:"Bracket", k:"Brace", l:"Ligature", n:"Nothing", s:"Separator", c:"Comment", a:"String" };
let keydesc='f+Conjugate;Add_f-Negate;Subtract_f×Sign;Multiply_f÷Reciprocal;Divide_f⋆Exponential;Power_f√Square Root;Root_f⌊Floor;Minimum_f⌈Ceiling;Maximum_f∧Sort Up;And_f∨Sort Down;Or_f¬Not;Span_f|Absolute Value;Modulus_f≤Less Than or Equal to_f<Enclose;Less Than_f>Merge;Greater Than_f≥Greater Than or Equal to_f=Rank;Equals_f≠Length;Not Equals_f≡Depth;Match_f≢Shape;Not Match_f⊣Identity;Left_f⊢Identity;Right_f⥊Deshape;Reshape_f∾Join;Join to_f≍Solo;Couple_f↑Prefixes;Take_f↓Suffixes;Drop_f↕Range;Windows_f«Shift Before_f»Shift After_f⌽Reverse;Rotate_f⍉Transpose;Reorder axes_f/Indices;Replicate_f⍋Grade Up;Bins Up_f⍒Grade Down;Bins Down_f⊏First Cell;Select_f⊑First;Pick_f⊐Index of_f⊒Occurrence Count;Progressive Index of_f∊Unique Mask;Member of_f⍷Deduplicate;Find_f⊔Group Indices;Group_f!Assert;Assert with message_m˙Constant_m˜Self/Swap_d∘Atop_d○Over_d⊸Before/Bind_d⟜After/Bind_d⌾Under_d⊘Valences_d◶Choose_d⎉Rank_m˘Cells_d⚇Depth_m¨Each_m⌜Table_d⍟Repeat_m⁼Undo_m´Fold_m˝Insert_m`Scan_g←Define_g⇐Export_g↩Change_g→Return_s⋄Separator_s,Separator_p(Begin expression_p)End expression_k{Begin block_k}End block_b⟨Begin list_b⟩End list_l‿Strand_n·Nothing_v•System_v𝕨Left argument_f𝕎Left argument (as function)_v𝕩Right argument_f𝕏Right argument (as function)_v𝕗Modifier left operand (as subject)_f𝔽Modifier left operand_v𝕘2-modifier right operand (as subject)_f𝔾2-modifier right operand_v𝕤Current function (as subject)_f𝕊Current function_m𝕣Current modifier_n¯Minus_nπPi_n∞Infinity_a@Null character_c#Comment'.split(/[\n_]/);
let kk=Array.from('`123456890-=~!@#$%^&*()_+qwertuiop[]QWERTIOP{}asdfghjkl;ASFGHKL:"zxcvbm,./XVBM<>? \'');
let kv=Array.from('˜˘¨⁼⌜´˝∞¯•÷׬⎉⚇⍟◶⊘⎊⍎⍕⟨⟩√⋆⌽𝕨∊↑∧⊔⊏⊐π←→↙𝕎⍷𝕣⍋⊑⊒⍳⊣⊢⍉𝕤↕𝕗𝕘⊸∘○⟜⋄↖𝕊𝔽𝔾«⌾»·˙⥊𝕩↓∨⌊≡∾≍≠𝕏⍒⌈≢≤≥⇐‿↩');
let keys={}, revkeys={};
kk.map((k,i)=>{keys[k]=kv[i];revkeys[kv[i]]=k;});
doc.kb.innerHTML = keydesc.map(d=>{
  let s = syncls[d[0]];
  let c = Array.from(d)[1];
  let t = d.slice(1+c.length).replace(';','\n');
  let k = revkeys[c]; if (k) t += '\n\\ '+(k==='"'?'&quot;':k);
  return '<span title="'+t+'" class="'+s+'">'+c+'</span>'
}).join("&#8203;"); // zero-width space
doc.kb.onmousedown = ev => {
  let t = ev.target;
  if (t.nodeName === 'SPAN') {
    return typeChar(doc.code, t.textContent, ev);
  }
}

if (doc.perm) doc.perm.onmouseover = doc.perm.onfocus = () => {
  let b=(new TextEncoder()).encode(doc.code.value);
  doc.perm.href='#code='+btoa(String.fromCharCode(...b));
}

let demo = 0;
if (doc.demo) doc.demo.onclick = () => {
  const demos = [
    '<⟜\'a\'⊸/ "Big Questions Notation"'
   ,'≠⌜˜ 8 ⥊ 0‿1'
   ,'+´ 1 + ↕100'
   ,'(+´ ÷ ≠) 2‿5‿7‿4'
   ,'+`-˝ "()" =⌜ "(2×(4-1)÷(√9))"'
   ,'(⊑ + ↕∘¬˜´) "CG"'
   ,'0‿1‿10‿100⊸⍋⊸⊔ ⟨6,11,9,20,105,1,¯1,4⟩'
   ,'{(+`𝕩<\'a\') ⊔ 𝕩} "camelCaseWord"'
   ,'3‿4‿2⌾(0‿0⊸⍉) 3‿3⥊¯1'
   ,'∾ (<˘ ≍¨¨ 1↓↓) "abcd"'
   ,'Life←{∨´1‿𝕩∧3‿4=+˝⥊⌽⟜𝕩¨∾⌜˜¯1‿0‿1}\nLife⍟(↕4) 6‿6↑(1⊸=∨5⊸≤)3‿3⥊↕9'
   ,'⥊ 1‿0‿1 ∧⌜⍟3 1'
   ,'⌈˝ (≠ ↕ 0‿0⊸∾) 1‿2‿5‿4‿0‿2‿1'
  ];
  ++demo; if (demo===demos.length) demo=0;
  doc.code.value = demos[demo]; repl();
}

if (location.hash) {
  let code='', run=1;
  location.hash.slice(1).split('&').map(s => {
    if (s.slice(0,5)==='code=') code=s.slice(5);
    if (s.slice(0,3)==='norun') run=0;
  });
  let b=atob(code);
  b=new Uint8Array([...b].map(c=>c.charCodeAt(0)));
  setcount(doc.code.value = (new TextDecoder()).decode(b));
  if (run) repl();
}
doc.code.focus();