Beweren en bewijzen/de zuilen/Zekerheid/5. Natuurlijke deductie/propositielogica stellingen
literatuur
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Hier een aantal stellingen in Coq-vorm waarmee je het bewijzen kunt oefenen, zowel met Coq als op papier.
Bedenk, alvorens met het bewijzen te beginnen, voorbeeld-invullingen voor P, Q enz.
<source lang="coq"> Theorem prop_001 : P /\ Q -> P. (*Elementary*) Theorem prop_005 : P /\ Q -> P \/ Q. (*Elementary*) Theorem prop_012 : (P -> Q) -> (P -> P /\ Q). (*Elementary*) Theorem prop_014 : ~(P /\ P) -> ~P \/ ~P. (*Easy*) Theorem prop_017 : P -> ~~P. (*Easy*) Theorem prop_018 : ~~(P -> Q) -> (P -> Q). (*Elementary*) Theorem prop_020 : ~~~P -> ~P. (*Medium*) Theorem prop_023 : ~(P -> Q) /\ Q -> ~P. (*Easy*) Theorem prop_024 : (P \/ Q) /\ ~P -> Q. (*Easy*) Theorem prop_025 : P -> ~Q \/ P /\ Q. (*Easy*) Theorem prop_026 : ~P /\ ~Q -> ~(P \/ ~P /\ Q). (*Medium*) Theorem prop_027 : ~(P \/ ~P /\ Q) -> ~P /\ ~Q. (*Medium*) Theorem prop_028 : ~(P \/ ~Q) \/ (~P /\ ~Q) -> ~P. (*Easy*) Theorem prop_029 : ~P -> ~(P \/ ~Q) \/ (~P /\ ~Q). (* Medium*) Theorem prop_031 : ~(P /\ Q /\ R) -> P -> Q -> ~R. (*Easy*) Theorem prop_032 : (P -> Q -> R) -> (Q /\ ~R -> ~P). (*Easy*) Theorem prop_033 : (P /\ Q -> ~R) -> (P /\ R -> ~Q). (*Easy*) Theorem prop_035 : (P -> Q -> R) /\ (P -> Q) -> (P -> R). (*Easy*) Theorem prop_036 : (P -> R) \/ (Q -> R) -> (P /\ Q -> R). (*Easy*) Theorem prop_037 : (P /\ Q -> R) -> (P -> R) \/ (Q -> R). (*Difficult*) Theorem prop_038 : ~((P /\ (R -> ~Q)) /\ (Q /\ (~R -> ~P))). (*Medium*) Theorem prop_039 : (P -> Q /\ R) /\ (Q \/ R -> ~P) -> ~P. (*Easy*) Theorem prop_040 : (P -> Q) /\ (Q -> R) -> (P -> R). (*Elementary*) Theorem prop_041 : ((P -> Q) /\ (Q -> R)) -> (P -> (Q -> R)). (*Elementary*) Theorem prop_044 : (P -> Q -> R) -> (P -> Q) -> P -> R. (*Easy*) Theorem prop_045 : P -> (Q -> Q). (*Elementary*) Theorem prop_046 : Q -> (P -> Q). (*Elementary*) Theorem prop_047 : P -> (P -> (Q -> P)). (*Elementary*) Theorem prop_048 : (P -> (P -> Q)) -> (P -> Q). (*Elementary*) Theorem prop_049 : (P -> Q -> ~P) -> ~P \/ ~Q. (*Easy*) Theorem prop_051 : P \/ Q -> ((P -> Q) -> Q). (*Easy*) Theorem prop_053 : ((P -> Q) -> Q) -> ~P -> Q. (*Easy*) Theorem prop_054 : ~P \/ ~Q -> (Q -> ~(Q -> P)). (*Medium*) Theorem prop_057 : ~(P -> Q) -> (Q -> P). (*Easy*) Theorem prop_059 : (P \/ Q -> ~R) /\ R -> ~P. (*Easy*) Theorem prop_060 : ~(P \/ Q) /\ (~Q -> R) -> R. (*Easy*) Theorem prop_061 : (P -> Q) /\ ~(P /\ Q) -> ~P. (*Easy*) Theorem prop_062 : (~P -> Q) /\ (~P -> ~Q) -> P. (*Easy*) Theorem prop_065 : P /\ Q \/ ~Q -> Q -> P /\ Q. (*Easy*) Theorem prop_066 : (P -> Q \/ R) -> ((P -> Q) \/ R). (*Medium*) Theorem prop_067 : (P /\ Q -> R) -> P -> (~Q \/ R). (*Easy*) Theorem prop_068 : (P -> R) -> (P /\ Q -> R). (*Elementary*) Theorem prop_069 : (P -> Q /\ R) -> ((R -> ~Q) -> ~P). (*Easy*) Theorem prop_070 : (P /\ Q -> ~R) -> (P /\ R -> ~Q). (*Easy*) Theorem prop_072 : (P -> Q /\ R) /\ (R \/ P) -> R. (*Easy*) Theorem prop_073 : (Q -> ~~R) -> (P -> Q -> P /\ R). (*Easy*) Theorem prop_074 : (P /\ (Q -> R)) -> Q -> (P /\ R). (*Elementary*) Theorem prop_075 : (Q \/ R) /\ (Q -> P) -> (~R -> P). (*Easy*) Theorem prop_076 : ((P -> Q) -> R) /\ (~P \/ Q) -> R. (*Easy*) Theorem prop_077 : ((~P \/ Q) -> (R /\ S)) -> (~S -> P). (*Easy*) Theorem prop_079 : (P \/ Q) -> (P -> R) -> (P -> Q \/ R). (*Elementary*) Theorem prop_080 : (P \/ Q -> (P -> R)) -> P -> (Q \/ R). (*Elementary*) Theorem prop_081 : (P \/ Q -> (P -> R)) -> Q -> (~P \/ R). (*Easy*) Theorem prop_082 : (P -> Q) /\ (R -> S) -> (~Q \/ ~S) -> (~P \/ ~R). (*Medium*) Theorem prop_083 : (P \/ Q -> R) -> (P -> R) \/ (Q -> R). (*Easy*) Theorem prop_084 : ((P \/ Q) -> R) -> (P -> R) /\ (~R -> ~Q). (*Easy*) Theorem prop_086 : (P \/ Q -> R) /\ (P \/ Q) -> (P -> R) \/ (Q -> R). (*Elementary*) Theorem prop_087 : (P -> R) /\ (R -> ~P) /\ (Q -> S) -> (P \/ Q -> S). (*Easy*) Theorem prop_088 : P -> (P /\ R -> Q) -> (((P -> Q) -> Q) -> (P -> R)) -> Q. (*Easy*) Theorem prop_089 : (R -> P \/ S) /\ (E -> Q \/ F) -> (R /\ E) -> (P /\ Q) \/ S \/ F. (*Medium*) Theorem prop_090 : (P -> R) /\ (Q -> S) /\ (P \/ Q) -> (R \/ S). (*Easy*) Theorem prop_092 : (P -> Q) \/ (Q -> P). (*Easy*) Theorem prop_099 : (P -> Q) -> (~Q -> ~P). (*Easy*) Theorem prop_100 : (~P -> ~Q) -> (Q -> P). (*Easy*) Theorem prop_101 : (P -> Q) -> (~~P -> ~~Q). (*Medium*) Theorem prop_102 : (~~P -> ~~Q) -> (P -> Q). (*Easy*) Theorem prop_103 : (~P \/ ~Q) -> ~(P /\ Q). (*Medium*) Theorem prop_104 : (P \/ Q) -> ~(~P /\ ~Q). (*Medium*) Theorem prop_105 : ~(P /\ Q) -> (~P \/ ~Q). (*Easy*) Theorem prop_106 : ~(~P /\ ~Q) -> (P \/ Q). (*Medium*) Theorem prop_107 : ~(P /\ Q) -> ~~ (~P \/ ~Q). (*Difficult*) Theorem prop_108 : ~(P \/ Q) -> (~P /\ ~Q). (*Easy*) Theorem prop_109 : ~(~P \/ ~Q) -> (P /\ Q). (*Medium*) Theorem prop_110 : (~P /\ ~Q) -> ~(P \/ Q). (*Easy*) Theorem prop_111 : (P /\ Q) -> ~(~P \/ ~Q). (*Medium*) Theorem prop_112 : ~(~P \/ ~Q) -> (~~P /\ ~~Q). (*Easy*) Theorem prop_113 : ~(~P \/ ~Q) -> ~~(P /\ Q). (*Difficult*) Theorem prop_119 : ~~P -> ~~(P \/ Q). (*Easy*) Theorem prop_120 : ~~(P /\ Q) -> ~~Q. (*Easy*) Theorem prop_121 : (P -> Q) /\ (P -> ~Q) -> ~P. (*Easy*) Theorem prop_122 : (Q -> R) -> (P \/ Q) -> (P \/ R). (*Easy*) Theorem prop_125 : ((P -> Q) -> P) -> P. (*Easy*) Theorem prop_126 : (~~(((P -> Q) -> P) -> P)). (*Difficult*) Theorem prop_128 : ~((P -> Q) /\ (Q -> ~P) /\ (~P -> ~Q) /\ (~Q -> P)). (*Medium*) </source>
- voor de liefhebbers
Hieronder nog een aantal stellingen die voor de verificatie van artefacten niet echt relevant zijn maar inzicht kunnen geven in hoe de logica zelf in elkaar zit.
<source lang="coq"> Theorem prop_002 : (~P -> P) -> P. (*Easy*) (*Een bewering kan alleen uit haar eigen negatie volgen als ze toch al waar was.*) Theorem prop_003 : (~P -> P) \/ ~P. (*Easy*) Theorem prop_016 : ~P \/ P. (*Difficult als LEM niet gebruikt mag worden, Easy als LEM wel gebruikt mag worden*) (*Het Uitgesloten Derde, alleen geldig in de klassieke logica.*) Theorem prop_021 : ~P \/ (Q -> P). (*Easy*) (*Classically, everything is false or implied*) Theorem prop_030 : ~P /\ ~Q -> ~((P -> Q) -> Q). (* Medium*) Theorem prop_034 : R -> ((~P -> ~R) -> ((P -> ~R) -> Q)). (*Easy*) Theorem prop_050 : ((P -> Q) -> P) -> ((Q -> P) -> P). (*Medium*) Theorem prop_055 : (Q -> ~(Q -> P)) -> (~P \/ ~Q). (*Easy*) Theorem prop_056 : (P -> Q) \/ (P /\ ~Q). (*Medium*) Theorem prop_058 : ~P /\ ((Q -> P) -> P) -> Q. (*Easy*) Theorem prop_063 : ~~((~P -> Q) /\ (~P -> ~Q) -> P). (*Difficult*) Theorem prop_085 : ~((P -> (Q \/ ~R)) /\ (Q -> ~P) /\ (P -> R) /\ P). (*Medium*) Theorem prop_117 : (~~P /\ ~~(P -> Q)) -> ~~Q. (*Difficult*) Theorem prop_118 : ~~(P \/ Q) -> (~~P -> ~~R) -> (~~Q -> ~~R) -> ~~R. (*Challenge*) Theorem prop_123 : ((P \/ (P -> Q)) -> Q) -> Q. (*Easy*) Theorem prop_124 : ~~(((P \/ (P -> Q)) -> Q) -> Q). (*Difficult*) Theorem prop_127 : (((((P -> Q) -> P) -> P) -> Q) -> Q). (*Easy*) </source>