well, instead of trees of the classical S-expression type that you are referring to here, which are what LISP is built on. I suggest you investigate a graph dat

well, instead of trees of the classical S-expression type that you are referring to here, which are what LISP is built on. I suggest you investigate a graph database like Neo4J which is way more fun than lousy S-expressions. But what are in the trees are numbers or strings (which are arrays of numbers). Frankly all the computer has are bits which form numbers, so that is not something you are going to get away from.