- ∀BT1,BT2.cic:/matita/formal_topology/basic_topologies/continuous_relation.ind#xpointer(1/1) BT1 BT2 →
- continuous_relation (o_basic_topology_of_basic_topology BT1) (o_basic_topology_of_basic_topology BT2).
+ ∀BT1,BT2.continuous_relation BT1 BT2 →
+ Ocontinuous_relation (o_basic_topology_of_basic_topology BT1) (o_basic_topology_of_basic_topology BT2).