-o-algebra.ma datatypes/categories.ma logic/cprop_connectives.ma
-o-formal_topologies.ma o-concrete_spaces.ma
+basic_pairs.ma o-basic_pairs.ma relations.ma
+o-algebra.ma categories.ma
+o-formal_topologies.ma o-basic_topologies.ma
+categories.ma cprop_connectives.ma
+subsets.ma categories.ma o-algebra.ma
+relations.ma o-algebra.ma subsets.ma