           if node.isConjunction
             extend body.vars,
               '⍵⍵': type: 'F', slot: 0, scopeDepth: d - 1
-              '∇∇': type: 'F', slot: 1, scopeDepth: d - 1, isAdverb: true, isConjunction: true
+              '⍹':  type: 'F', slot: 0, scopeDepth: d - 1
+              '∇∇': type: 'F', slot: 1, scopeDepth: d - 1, isConjunction: true
               '⍺⍺': type: 'F', slot: 2, scopeDepth: d - 1
+              '⍶':  type: 'F', slot: 2, scopeDepth: d - 1
           else if node.isAdverb
             extend body.vars,
               '⍺⍺': type: 'F', slot: 0, scopeDepth: d - 1
-              '∇∇': type: 'F', slot: 1, scopeDepth: d - 1, isAdverb: true, isConjunction: true
+              '⍶':  type: 'F', slot: 0, scopeDepth: d - 1
+              '∇∇': type: 'F', slot: 1, scopeDepth: d - 1, isAdverb: true
           type: 'F', isAdverb: node.isAdverb, isConjunction: node.isConjunction
         when 'string', 'number', 'embedded' then {type: 'X'}
         when 'index'

      when 'string', 'number', 'embedded' then 0
      when 'symbol'
        switch node[1]
          when '⍺⍺', '∇∇' then 1
          when '⍵⍵' then 3
          else 0
      else throw Error "Unrecognized node type, '#{node[0]}'"
  ) ast

        # {⍵<2 : 1 ⋄ (∇⍵-1)+(∇⍵-2) } 8 <=> 34 # Fibonacci sequence
        # ⊂{⍺⍺ ⍺⍺ ⍵}'hello'            <=> ⊂⊂'hello'
        # ⊂{⍺⍺ ⍵⍵ ⍵}⌽'hello'           <=> ⊂'olleh'
        # ⊂{⍶⍶⍵}'hello'                <=> ⊂⊂'hello'
        # ⊂{⍶⍹⍵}⌽'hello'               <=> ⊂'olleh'
        code = render node[1]
        if node.isAdverb or node.isConjunction
          [LAM, code.length + 3, LAM, code.length].concat code, RET
