X-Git-Url: https://svn.cri.ensmp.fr/git/linpy.git/blobdiff_plain/4ae512f39c14835badbfab6fc1ce877f601d104e..d06ab92943ec2e10a2bd798ca7c1b5cea395bf34:/pypol/domains.py

diff --git a/pypol/domains.py b/pypol/domains.py
index c844e55..abc2d91 100644
--- a/pypol/domains.py
+++ b/pypol/domains.py
@@ -50,7 +50,7 @@ class Domain:
         symbols = set()
         for item in iterator:
             symbols.update(item.symbols)
-        return tuple(sorted(symbols))
+        return tuple(sorted(symbols, key=lambda symbol: symbol.name))
 
     @property
     def polyhedra(self):
@@ -155,11 +155,15 @@ class Domain:
     def project_out(self, symbols):
         # use to remove certain variables
         islset = self._toislset(self.polyhedra, self.symbols)
-        # the trick is to walk symbols in reverse order, to avoid index updates
+        n = 0
         for index, symbol in reversed(list(enumerate(self.symbols))):
             if symbol in symbols:
-                islset = libisl.isl_set_project_out(islset, libisl.isl_dim_set, index, 1)
-        # remaining symbols
+                n += 1
+            elif n > 0:
+                islset = libisl.isl_set_project_out(islset, libisl.isl_dim_set, index + 1, n)
+                n = 0
+        if n > 0:
+            islset = libisl.isl_set_project_out(islset, libisl.isl_dim_set, 0, n)
         symbols = [symbol for symbol in self.symbols if symbol not in symbols]
         return Domain._fromislset(islset, symbols)
 
@@ -336,6 +340,7 @@ class Domain:
     def tosympy(self):
         raise NotImplementedError
 
+
 def And(*domains):
     if len(domains) == 0:
         from .polyhedra import Universe