Prove: $(Arightarrow B),(Arightarrow C)rightarrow B, mapsto_{HPC} B $












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I'd really like your help proving:



$(Arightarrow B),(Arightarrow C)rightarrow B, mapsto_{HPC} B $



Where $HPC$ is the Hilbert's system proof which contains the following relevant axioms:




  1. $Arightarrow(B rightarrow A)$

  2. $(Arightarrow(Brightarrow C)) to ((Arightarrow B)rightarrow(Arightarrow C))$

  3. $(Arightarrow B)rightarrow ((Arightarrowbar{B})rightarrow bar{A})$

  4. $bar{bar{A}} rightarrow A$


In addition tried to use these following lemmas: $bar{A} rightarrow (A rightarrow C) $ and $(Arightarrow B)rightarrow (bar{B} rightarrow bar{A})$.



Any suggestions?










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    0












    $begingroup$


    I'd really like your help proving:



    $(Arightarrow B),(Arightarrow C)rightarrow B, mapsto_{HPC} B $



    Where $HPC$ is the Hilbert's system proof which contains the following relevant axioms:




    1. $Arightarrow(B rightarrow A)$

    2. $(Arightarrow(Brightarrow C)) to ((Arightarrow B)rightarrow(Arightarrow C))$

    3. $(Arightarrow B)rightarrow ((Arightarrowbar{B})rightarrow bar{A})$

    4. $bar{bar{A}} rightarrow A$


    In addition tried to use these following lemmas: $bar{A} rightarrow (A rightarrow C) $ and $(Arightarrow B)rightarrow (bar{B} rightarrow bar{A})$.



    Any suggestions?










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      I'd really like your help proving:



      $(Arightarrow B),(Arightarrow C)rightarrow B, mapsto_{HPC} B $



      Where $HPC$ is the Hilbert's system proof which contains the following relevant axioms:




      1. $Arightarrow(B rightarrow A)$

      2. $(Arightarrow(Brightarrow C)) to ((Arightarrow B)rightarrow(Arightarrow C))$

      3. $(Arightarrow B)rightarrow ((Arightarrowbar{B})rightarrow bar{A})$

      4. $bar{bar{A}} rightarrow A$


      In addition tried to use these following lemmas: $bar{A} rightarrow (A rightarrow C) $ and $(Arightarrow B)rightarrow (bar{B} rightarrow bar{A})$.



      Any suggestions?










      share|cite|improve this question











      $endgroup$




      I'd really like your help proving:



      $(Arightarrow B),(Arightarrow C)rightarrow B, mapsto_{HPC} B $



      Where $HPC$ is the Hilbert's system proof which contains the following relevant axioms:




      1. $Arightarrow(B rightarrow A)$

      2. $(Arightarrow(Brightarrow C)) to ((Arightarrow B)rightarrow(Arightarrow C))$

      3. $(Arightarrow B)rightarrow ((Arightarrowbar{B})rightarrow bar{A})$

      4. $bar{bar{A}} rightarrow A$


      In addition tried to use these following lemmas: $bar{A} rightarrow (A rightarrow C) $ and $(Arightarrow B)rightarrow (bar{B} rightarrow bar{A})$.



      Any suggestions?







      logic propositional-calculus proof-theory hilbert-calculus






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      edited Jul 29 '18 at 12:25









      Taroccoesbrocco

      5,42271839




      5,42271839










      asked Mar 21 '13 at 17:14









      JozefJozef

      2,84132564




      2,84132564






















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          $begingroup$


          1. $A→B$ (premise)

          2. $(A→C)→B$ (premise)

          3. $(A→B)→(neg B→neg A)$ (your second lemma)

          4. $neg B→ neg A$ (3,1)

          5. $neg A →(A→C)$ (your first lemma)

          6. $(neg A →(A→C))→(neg B → (neg A →(A→C)))$ (axiom 1)

          7. $neg B → (neg A →(A→C))$ (6,5)

          8. $(neg B → (neg A →(A→C))) → ((neg B → neg A)→(neg B → (A→C)))$ (axiom 2)

          9. $((neg B → neg A)→(neg B → (A→C)))$ (8,7)

          10. $neg B → (A→C)$ (9,4)

          11. $((A→C)→B)→(neg B → neg(A→C))$ (your second lemma)

          12. $neg B → neg(A→C)$ (11, 2)

          13. $(neg B → (A→C))→((neg B → neg(A→C))→neg neg B)$ (axiom 3)

          14. $(neg B → neg(A→C))→neg neg B$ (13, 10)

          15. $neg neg B$ (14, 12)

          16. $neg neg B → B$ (axiom 4)

          17. $B$ (16, 15)






          share|cite|improve this answer









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            $begingroup$


            1. $A→B$ (premise)

            2. $(A→C)→B$ (premise)

            3. $(A→B)→(neg B→neg A)$ (your second lemma)

            4. $neg B→ neg A$ (3,1)

            5. $neg A →(A→C)$ (your first lemma)

            6. $(neg A →(A→C))→(neg B → (neg A →(A→C)))$ (axiom 1)

            7. $neg B → (neg A →(A→C))$ (6,5)

            8. $(neg B → (neg A →(A→C))) → ((neg B → neg A)→(neg B → (A→C)))$ (axiom 2)

            9. $((neg B → neg A)→(neg B → (A→C)))$ (8,7)

            10. $neg B → (A→C)$ (9,4)

            11. $((A→C)→B)→(neg B → neg(A→C))$ (your second lemma)

            12. $neg B → neg(A→C)$ (11, 2)

            13. $(neg B → (A→C))→((neg B → neg(A→C))→neg neg B)$ (axiom 3)

            14. $(neg B → neg(A→C))→neg neg B$ (13, 10)

            15. $neg neg B$ (14, 12)

            16. $neg neg B → B$ (axiom 4)

            17. $B$ (16, 15)






            share|cite|improve this answer









            $endgroup$


















              4












              $begingroup$


              1. $A→B$ (premise)

              2. $(A→C)→B$ (premise)

              3. $(A→B)→(neg B→neg A)$ (your second lemma)

              4. $neg B→ neg A$ (3,1)

              5. $neg A →(A→C)$ (your first lemma)

              6. $(neg A →(A→C))→(neg B → (neg A →(A→C)))$ (axiom 1)

              7. $neg B → (neg A →(A→C))$ (6,5)

              8. $(neg B → (neg A →(A→C))) → ((neg B → neg A)→(neg B → (A→C)))$ (axiom 2)

              9. $((neg B → neg A)→(neg B → (A→C)))$ (8,7)

              10. $neg B → (A→C)$ (9,4)

              11. $((A→C)→B)→(neg B → neg(A→C))$ (your second lemma)

              12. $neg B → neg(A→C)$ (11, 2)

              13. $(neg B → (A→C))→((neg B → neg(A→C))→neg neg B)$ (axiom 3)

              14. $(neg B → neg(A→C))→neg neg B$ (13, 10)

              15. $neg neg B$ (14, 12)

              16. $neg neg B → B$ (axiom 4)

              17. $B$ (16, 15)






              share|cite|improve this answer









              $endgroup$
















                4












                4








                4





                $begingroup$


                1. $A→B$ (premise)

                2. $(A→C)→B$ (premise)

                3. $(A→B)→(neg B→neg A)$ (your second lemma)

                4. $neg B→ neg A$ (3,1)

                5. $neg A →(A→C)$ (your first lemma)

                6. $(neg A →(A→C))→(neg B → (neg A →(A→C)))$ (axiom 1)

                7. $neg B → (neg A →(A→C))$ (6,5)

                8. $(neg B → (neg A →(A→C))) → ((neg B → neg A)→(neg B → (A→C)))$ (axiom 2)

                9. $((neg B → neg A)→(neg B → (A→C)))$ (8,7)

                10. $neg B → (A→C)$ (9,4)

                11. $((A→C)→B)→(neg B → neg(A→C))$ (your second lemma)

                12. $neg B → neg(A→C)$ (11, 2)

                13. $(neg B → (A→C))→((neg B → neg(A→C))→neg neg B)$ (axiom 3)

                14. $(neg B → neg(A→C))→neg neg B$ (13, 10)

                15. $neg neg B$ (14, 12)

                16. $neg neg B → B$ (axiom 4)

                17. $B$ (16, 15)






                share|cite|improve this answer









                $endgroup$




                1. $A→B$ (premise)

                2. $(A→C)→B$ (premise)

                3. $(A→B)→(neg B→neg A)$ (your second lemma)

                4. $neg B→ neg A$ (3,1)

                5. $neg A →(A→C)$ (your first lemma)

                6. $(neg A →(A→C))→(neg B → (neg A →(A→C)))$ (axiom 1)

                7. $neg B → (neg A →(A→C))$ (6,5)

                8. $(neg B → (neg A →(A→C))) → ((neg B → neg A)→(neg B → (A→C)))$ (axiom 2)

                9. $((neg B → neg A)→(neg B → (A→C)))$ (8,7)

                10. $neg B → (A→C)$ (9,4)

                11. $((A→C)→B)→(neg B → neg(A→C))$ (your second lemma)

                12. $neg B → neg(A→C)$ (11, 2)

                13. $(neg B → (A→C))→((neg B → neg(A→C))→neg neg B)$ (axiom 3)

                14. $(neg B → neg(A→C))→neg neg B$ (13, 10)

                15. $neg neg B$ (14, 12)

                16. $neg neg B → B$ (axiom 4)

                17. $B$ (16, 15)







                share|cite|improve this answer












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                answered Mar 23 '13 at 17:04









                CianCian

                411215




                411215






























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