+0.6.4 (10 August 2000)
+* Complete revamp of methods in class matrix. Some redundant (and poor)
+ implementations of elimination schemes were thrown out. The code is now
+ highly orthogonal, more flexible and much more efficient.
+* Some long standing and quite nasty bugs were discovered and fixed in the
+ following functions: add::normal(), heur_gcd(), sr_gcd() and Order_eval().
+