+inductive And (A,B:Type) : Type ≝
+ | Conj : A → B → And A B.
+
+interpretation "constructive and" 'and x y =
+ (cic:/matita/constructive_connectives/And.ind#xpointer(1/1) x y).
+
+inductive exT (A:Type) (P:A→Type) : Type ≝
+ ex_introT: ∀w:A. P w → exT A P.
+
+inductive ex (A:Type) (P:A→Prop) : Type ≝
+ ex_intro: ∀w:A. P w → ex A P.
+
+(*
+notation < "hvbox(Σ ident i opt (: ty) break . p)"
+ right associative with precedence 20
+for @{ 'sigma ${default
+ @{\lambda ${ident i} : $ty. $p)}
+ @{\lambda ${ident i} . $p}}}.
+*)
+
+interpretation "constructive exists" 'exists \eta.x =
+ (cic:/matita/constructive_connectives/ex.ind#xpointer(1/1) _ x).
+interpretation "constructive exists (Type)" 'exists \eta.x =
+ (cic:/matita/constructive_connectives/exT.ind#xpointer(1/1) _ x).
+
+alias id "False" = "cic:/matita/logic/connectives/False.ind#xpointer(1/1)".
+definition Not ≝ λx:Type.x → False.
+
+interpretation "constructive not" 'not x =
+ (cic:/matita/constructive_connectives/Not.con x).