SENTENCE -> LAMBDA

1. A rename
OVERRIDE

* BEWARE: of Symbol Lookup() when it;s not ToUpper() can cause big
trouble.
1. Improved OVERRIDE: to both override words in dict and value in
instance.
2. Added CHAINS: to aid OVERRIDE
3. GETMEMBER -> ">>" : The extract function.
4. SYMBOL and TAG are no longer use "-" or "?"
=> NUMBER? -> ISNUMBER .