       when 'string', 'number', 'embedded' then 0
       when 'symbol'
         switch node[1]
-          when '⍺⍺', '∇∇' then 1
-          when '⍵⍵' then 3
+          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'
        code = render node[1]
        if node.isAdverb or node.isConjunction
          [LAM, code.length + 3, LAM, code.length].concat code, RET

          if node.isConjunction
            extend body.vars,
              '⍵⍵': type: 'F', slot: 0, scopeDepth: d - 1
              '⍹':  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: 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'
