include "Plogic/equality.ma".
-ninductive True: Prop ≝
+inductive True: Prop ≝
I : True.
-default "true" cic:/matita/basics/connectives/True.ind.
-
-ninductive False: Prop ≝ .
-
-default "false" cic:/matita/basics/connectives/False.ind.
+inductive False: Prop ≝ .
(*
ndefinition Not: Prop → Prop ≝
λA. A → False. *)
-ninductive Not (A:Prop): Prop ≝
+inductive Not (A:Prop): Prop ≝
nmk: (A → False) → Not A.
interpretation "logical not" 'not x = (Not x).
-ntheorem absurd : ∀ A:Prop. A → ¬A → False.
-#A; #H; #Hn; nelim Hn;/2/; nqed.
+theorem absurd : ∀ A:Prop. A → ¬A → False.
+#A; #H; #Hn; elim Hn;/2/; qed.
(*
ntheorem absurd : ∀ A,C:Prop. A → ¬A → C.
#A; #C; #H; #Hn; nelim (Hn H).
nqed. *)
-ntheorem not_to_not : ∀A,B:Prop. (A → B) → ¬B →¬A.
-/4/; nqed.
+theorem not_to_not : ∀A,B:Prop. (A → B) → ¬B →¬A.
+/4/; qed.
-ninductive And (A,B:Prop) : Prop ≝
+inductive And (A,B:Prop) : Prop ≝
conj : A → B → And A B.
interpretation "logical and" 'and x y = (And x y).
-ntheorem proj1: ∀A,B:Prop. A ∧ B → A.
-#A; #B; #AB; nelim AB; //.
-nqed.
+theorem proj1: ∀A,B:Prop. A ∧ B → A.
+#A; #B; #AB; elim AB; //.
+qed.
-ntheorem proj2: ∀ A,B:Prop. A ∧ B → B.
-#A; #B; #AB; nelim AB; //.
-nqed.
+theorem proj2: ∀ A,B:Prop. A ∧ B → B.
+#A; #B; #AB; elim AB; //.
+qed.
-ninductive Or (A,B:Prop) : Prop ≝
+inductive Or (A,B:Prop) : Prop ≝
or_introl : A → (Or A B)
| or_intror : B → (Or A B).
interpretation "logical or" 'or x y = (Or x y).
-ndefinition decidable : Prop → Prop ≝
+definition decidable : Prop → Prop ≝
λ A:Prop. A ∨ ¬ A.
-ninductive ex (A:Type[0]) (P:A → Prop) : Prop ≝
+inductive ex (A:Type[0]) (P:A → Prop) : Prop ≝
ex_intro: ∀ x:A. P x → ex A P.
interpretation "exists" 'exists x = (ex ? x).
-ninductive ex2 (A:Type[0]) (P,Q:A \to Prop) : Prop ≝
+inductive ex2 (A:Type[0]) (P,Q:A \to Prop) : Prop ≝
ex_intro2: ∀ x:A. P x → Q x → ex2 A P Q.
-ndefinition iff :=
+definition iff :=
λ A,B. (A → B) ∧ (B → A).
interpretation "iff" 'iff a b = (iff a b).