initial version of proposition parsing and function generation
added select macro imlementation
added funtion for theta-join
added semijoin function
beginnings of expression tree
removed use of macros and added more expression evaluation
more evals
first simple expression parsing and AST generating
new version of select macro
added expand-select and rebuilt select macro
added first version of expand-query
first pass at query macro
added expand-renames support to expand-select
first pass at renaming
tested renaming with query execution