(Program
  (SubscriptAccess
  { (Identifier)
  ->(Identifier) }
  { (Identifier)
  ->(StringLiteral) })
  (SubscriptAccess
  { (Identifier)
  ->(Identifier) }
  { (SymbolLiteral)
  ->(SymbolLiteral) })
{-(Assignment
    (SubscriptAccess
      (Identifier)
      (Identifier))
    (IntegerLiteral))-})