[Maxima-commits] CVS: maxima/share/algebra/solver misc.mac, 1.2, 1.3

[Andrej V. <an...@us...>]

Update of /cvsroot/maxima/maxima/share/algebra/solver
In directory sc8-pr-cvs7.sourceforge.net:/tmp/cvs-serv7905

Modified Files:
	misc.mac 
Log Message:
Reimplement Setify, Union and Intersection so that they don't use 
functions from nset. This is needed because Solver expects that the 
order of elements in the list is not changed with this functions and 
functions from nset change the order of elements.


Index: misc.mac
===================================================================
RCS file: /cvsroot/maxima/maxima/share/algebra/solver/misc.mac,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -d -r1.2 -r1.3
--- misc.mac	21 Apr 2006 00:45:57 -0000	1.2
+++ misc.mac	3 Jan 2007 09:35:41 -0000	1.3
@@ -63,13 +63,23 @@
 /* Solver does not know maxima sets - workarounds for set functions.          */
 /******************************************************************************/
 
-Setify(lst) := listify(setify(lst))$
+Setify(lst) :=
+  if length(lst)=0 then []
+  else append([lst[1]], Setify(delete(lst[1], lst)))$
 
 DisjointP(l1, l2) := disjointp(setify(l1), setify(l2))$
 
-Intersection(l1, l2) := listify(intersection(setify(l1), setify(l2)))$
+Intersection(l1, l2) :=
+  if length(l1)=0 then []
+  else if member(l1[1], l2) then append([l1[1]], Intersection(rest(l1), l2))
+  else Intersection(rest(l1), l2)$
 
 SetDifference(l1, l2) := listify(setdifference(setify(l1), setify(l2)))$
 
-Union([l]) := listify(lreduce(union, map(setify, l)))$
+Union([l]) := lreduce(Union2, l)$
+
+Union2(l1, l2) :=
+  if length(l2)=0 then l1
+  else if not(member(l2[1], l1)) then Union2(append(l1, [l2[1]]), rest(l2))
+  else Union2(l1, rest(l2))$