Induction.ConjunctiveFalseness

(*
    CoMoEx - Example of inductive proofs: Conjunctive Falseness
    Copyright (C) 2024  Max Ole Elliger

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *)


From Induction Require Export Intro.

Einschränkung der Grammatik


Fixpoint only_top_bottom_atom_conjunction (f : formula) : Prop :=
  
Die folgende Zeile einfach durch eine passende Definition ersetzen!
  True.

In den nachfolgenden Beispielen einfach Admitted durch Qed ersetzen!

Local Example sanity_check_top :
  only_top_bottom_atom_conjunction top.
Proof.
  firstorder.
Admitted.

Local Example sanity_check_bottom :
  only_top_bottom_atom_conjunction bottom.
Proof.
  firstorder.
Admitted.

Local Example sanity_check_atom :
  forall a,
    only_top_bottom_atom_conjunction (atom a).
Proof.
  firstorder.
Admitted.

Local Example sanity_check_negation :
  forall f,
    ~ only_top_bottom_atom_conjunction (negation f).
Proof.
  firstorder.
Admitted.

Local Example sanity_check_conjunction :
  forall f1 f2,
    only_top_bottom_atom_conjunction f1 ->
    only_top_bottom_atom_conjunction f2 ->
    only_top_bottom_atom_conjunction (conjunction f1 f2).
Proof.
  firstorder.
Admitted.

Local Example sanity_check_disjunction :
  forall f1 f2,
    ~ only_top_bottom_atom_conjunction (disjunction f1 f2).
Proof.
  firstorder.
Admitted.

Local Example sanity_check_implication :
  forall f1 f2,
    ~ only_top_bottom_atom_conjunction (implication f1 f2).
Proof.
  firstorder.
Admitted.

Local Example sanity_check_biimplication :
  forall f1 f2,
    ~ only_top_bottom_atom_conjunction (biimplication f1 f2).
Proof.
  firstorder.
Admitted.

Beweis der konjunktiven Falschheit


Theorem conjunctive_falseness :
  forall (f : formula) (a : string) (k : wb),
    k (a) = false ->
    atom_occurs (f) (a) ->
    only_top_bottom_atom_conjunction (f) ->
    ~ satisfaction k f.
Proof.
Admitted.