         # A×A←2 5 <=> 4 25
         render(node[2]).concat renderLHS node[1]
       when 'symbol'
-        # radius ← 3
-        # ... get_circumference ← {2×○radius}
-        # ... get_surface ← {○radius*2}
-        # ...
-        # ... before ← 0.01× ⌊ 100× radius circumference surface
-        # ... radius ← radius + 1
-        # ... after  ← 0.01× ⌊ 100× radius circumference surface
-        # ...
-        # ... before after
-        # ... <=> (3 18.84 28.27)(4 25.13 50.26)
+        # r←3 ⋄ get_c←{2×○r} ⋄ get_S←{○r*2}
+        # ... before←.01×⌊100×r c S
+        # ... r←r+1
+        # ... after←.01×⌊100×r c S
+        # ... before after <=> (3 18.84 28.27)(4 25.13 50.26)
         name = node[1]
         {vars} = node.scopeNode
         if (v = vars["get_#{name}"])?.type is 'F'

            scopeNode: scopeNode
            scopeDepth: (d = scopeNode.scopeDepth + 1 + !!(node.isAdverb or node.isConjunction))
            nSlots: 3
            vars: extend Object.create(vars),
              '⍵': type: 'X', slot: 0, scopeDepth: d
              '∇': type: 'F', slot: 1, scopeDepth: d
              '⍺': type: 'X', slot: 2, scopeDepth: d
          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'
          for i in [2...node.length] by 1 when c = node[i]
            visit(c).type is 'X' or err node, 'Only expressions of type data can be used as an index.'
          visit node[1]
        when 'expr'
          a = node[1...]
          h = Array a.length
          for i in [a.length - 1 .. 0]
            h[i] = visit a[i]
          # Form vectors from sequences of data
          i = 0
          while i < a.length - 1

        when 'symbol'
          name = node[1]
          if (v = vars["get_#{name}"])?.type is 'F'
            type: 'X'
          else
            vars[name] or err node, "Symbol '#{name}' is referenced before assignment."
        when 'lambda'
