root and sqrt on negative inputs
authorhuffman
Mon May 14 19:14:50 2007 +0200 (2007-05-14)
changeset 22971a6812b6a36a5
parent 22970 b5910e3dec4c
child 22972 3e96b98d37c6
root and sqrt on negative inputs
NEWS
     1.1 --- a/NEWS	Mon May 14 18:48:24 2007 +0200
     1.2 +++ b/NEWS	Mon May 14 19:14:50 2007 +0200
     1.3 @@ -868,6 +868,12 @@
     1.4  feature is used only for decision, for compatibility with arith. This
     1.5  means a goal is either solved or left unchanged, no simplification.
     1.6  
     1.7 +* Hyperreal: Functions root and sqrt are now defined on negative real
     1.8 +inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
     1.9 +Nonnegativity side conditions have been removed from many lemmas, so
    1.10 +that more subgoals may now be solved by simplification; potential
    1.11 +INCOMPATIBILITY.
    1.12 +
    1.13  * Real: New axiomatic classes formalize real normed vector spaces and
    1.14  algebras, using new overloaded constants scaleR :: real => 'a => 'a
    1.15  and norm :: 'a => real.