** the type system is now cleverer about negations of numeric
types, and consequently understands the BIGNUM and RATIO types
better;
+ ** the type system is now cleverer about the interaction between
+ INTEGER and RATIO types: while bugs still remain, many more
+ cases are accurately computed;
+ ** in TYPECASE, OTHERWISE now only introduces an otherwise-clause
+ if it is in the last clause;
+ ** CONSTANTLY now correctly returns a side-effect-free function in
+ all cases;
planned incompatible changes in 0.7.x:
* (not done yet, but planned:) When the profiling interface settles