--- /dev/null
+(**************************************************************************)
+(* ___ *)
+(* ||M|| *)
+(* ||A|| A project by Andrea Asperti *)
+(* ||T|| *)
+(* ||I|| Developers: *)
+(* ||T|| The HELM team. *)
+(* ||A|| http://helm.cs.unibo.it *)
+(* \ / *)
+(* \ / This file is distributed under the terms of the *)
+(* v GNU General Public License Version 2 *)
+(* *)
+(**************************************************************************)
+
+set "baseuri" "cic:/matita/constructive_higher_order_relations".
+
+include "constructive_connectives.ma".
+
+definition cotransitive ≝
+ λC:Type.λlt:C→C→Type.∀x,y,z:C. lt x y → lt x z ∨ lt z y.
+
+definition coreflexive ≝ λC:Type.λlt:C→C→Type. ∀x:C. ¬ (lt x x).
+
+definition antisymmetric ≝
+ λC:Type.λle:C→C→Type.λeq:C→C→Type.∀x,y:C.le x y → le y x → eq x y.
+
+definition symmetric ≝
+ λC:Type.λle:C→C→Type.∀x,y:C.le x y → le y x.
+
+definition transitive ≝
+ λC:Type.λle:C→C→Type.∀x,y,z:C.le x y → le y z → le x z.