lambda length
nlambda quote
lambda set
-macro setq
+macro setq set!
nlambda cond
nlambda progn
nlambda while
lexpr times *
lexpr divide /
lexpr mod %
-lexpr equal =
+lexpr equal = eq? eqv?
lexpr less <
lexpr greater >
lexpr less_equal <=
lambda collect
lambda nullp null?
lambda not
+lambda listp list?
+lambda pairp pair?