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NX .�Mb +2i 2t2KTH2- Ŀ +2i �`;mK2Mi 2bi p�HB/2 ŀ 7�Bi T�`iB2 /m H�M;�;2 Q#D2i- TmBb[mǶBH bǶ�;Bi /ǶmM2 �{`K�iBQMTQ`i�Mi bm` mM Q#D2i UmM �`;mK2Mi 2M HǶQ++m``2M+2V 2i ĿĿ +2i �`;mK2Mi 2bi p�HB/2 ŀ 2bi p`�B Qm 7�mt ŀ 7�Bi T�`iB2/m Kûi�H�M;�;2- TmBb[mǶBH bǶ�;Bi /ǶmM2 �{`K�iBQM TQ`i�Mi bm` /2b KQib Ubm` H2 H�M;�;2 KāK2 2i MQM H2b Q#D2ib[mǶBH /ûMQi2VX aB MQmb `2KTH�ÏQMb Ŀ +2i �`;mK2Mi ŀ T�` mM �mi`2 MQK /2 HǶ�`;mK2Mi /QMi MQmb pQmHQMb T�`H2`-T�` 2t2KTH2 T�` ĿĿ aB DǶûim/B2 H� HQ;B[m2- D2 b2`�B ?2m`2mt 2i b�;2 c DǶûim/B2 H� HQ;B[m2 c /QM+ D2 b2`�B ?2m`2mt 2ib�;2 ŀŀ- MQmb pQvQMb [m2 Ŀ +2i �`;mK2Mi 2bi p�HB/2 ŀ- ¨ bQM iQm`- �TT�`iB2Mi ¨ mM Kûi�H�M;�;2 T�` `�TTQ`i �mH�M;�;2 /QMi MQmb MQmb b2`pQMb TQm` T�`H2` /m #QM?2m` 2M;2M/`û T�` H� HQ;B[m2X

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dy jX _2H�iBQMb HQ;B[m2b 2i BM7û`2M+2b HQ;B[m2b

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�m HB2m /2 UjXj′′V- T�` 2t2KTH2- QM T2mi /QM+ �mbbB /B`2 ,

UjXj′′′V AH 2bi p`�B [m2 Ŀ aB DǶûim/B2 H� HQ;B[m2- D2 b2`�B ?2m`2mt 2i b�;2 c DǶûim/B2 H� HQ;B[m2 c/QM+ D2 b2`�B ?2m`2mt 2i b�;2 ŀ 2bi p�HB/2X

UjXj′′′V- +QKK2 UjXj′′V- �TT�`iB2Mi �m Kûi�H�M;�;2 T�` `�TTQ`i ¨ UjXk′′VX �m HB2m /2 UjXk′′V- MQmbTQmpQMb miBHBb2` HǶQTû`�i2m` T`QTQbBiBQMM2H #BM�B`2 Ŀ ûi�Mi /QMMû [m2 Ę- BH bǶ2MbmBi /2 · · · ŀ UmMQTû`�i2m` [mB T`2M/ /2mt T?`�b2b TQm` 2M 7�B`2 mM2 i`QBbBĕK2V ,

UjXk′′′V úi�Mi /QMMû [m2 bB DǶûim/B2 H� HQ;B[m2- D2 b2`�B ?2m`2mt 2i b�;2- 2i [m2 DǶûim/B2 H�HQ;B[m2- BH bǶ2MbmBi [m2 D2 b2`�B ?2m`2mt 2i b�;2X

AH 2bi 2bb2MiB2H /2 M2 T�b +QM7QM/`2 +2ii2 `2H�iBQM /2 Ŀ ûi�Mi /QMMû [m2 Ę- BH bǶ2MbmBi [m2 · · · ŀ�p2+ H� `2H�iBQM /2 Ŀ bB Ę �HQ`b · · · ŀX Ŀ aB Ę �HQ`b · · · ŀ 2bi mM2 2tT`2bbBQM [mB �TT�`iB2Mi �mH�M;�;2@Q#D2i , 2HH2 T`2M/ UmiBHBb2V /2mt T?`�b2b TQm` 2M 7�B`2 mM2 i`QBbBĕK2X Ŀ úi�Mi /QMMû [m2 Ę-BH bǶ2MbmBi [m2 · · · ŀ- �m +QMi`�B`2- �TT�`iB2Mi �m Kûi�H�M;�;2 2i MQmb b2`i ¨ /B`2 U2M K2MiBQMM�MiH2b T?`�b2bV [mǶBH v � mM2 `2H�iBQM /2 +QMbû[m2M+2 HQ;B[m2 2Mi`2 /2mt T?`�b2b- [m2 HǶmM2 bǶ2MbmBi/2 HǶ�mi`2X LQmb �#`û;2QMb H� `2H�iBQM 2tT`BKû2 T�` Ŀ ûi�Mi /QMMû [m2 Ę- BH bǶ2MbmBi [m2 · · · ŀT�` mM MQmp2�m bB;M2- Ŀ |4 ŀXRR SHmb ;ûMû`�H2K2Mi- TQm` T�`H2` /ǶmM2 `2H�iBQM /2 +QMbû[m2M+2Kûi�HBM;mBbiB[m2 UMQM@bTû+B}û2V- MQmb miBHBbQMb H� ~ĕ+?2 HQM;m2 2i Ł ûT�Bbb2 ł Ŀ 4⇒ ŀ- TQm` 7�B`2mM +QMi`�bi2 �p2+ H� ~ĕ+?2 Ł bBKTH2 ł Ŀ → ŀ [m2 MQmb miBHBbQMb TQm` H� `2H�iBQM 2tT`BKû2 T�`Ŀ bB Ę �HQ`b · · · ŀX 1M HB2m 2i TH�+2 /2 ,

UjXdV Ŀ aB p �HQ`b q ŀ 2bi p`�B bbB bB Ŀ p ŀ 2bi p`�B �HQ`b Ŀ q ŀ HǶ2bi �mbbBX

MQmb TQm``QMb /QM+ K�BMi2M�Mi /B`2

UjXd′V Ŀ p→ q ŀ 2bi p`�B bbB p 4⇒ q

AH M2 bǶ�;Bi T�b B+B /ǶBMi`Q/mB`2 mM MQmp2�m 7Q`K�HBbK2- K�Bb /Ƕ�#`û;2` /2 K�MBĕ`2 b2KB@7Q`K2HH2/2b HQ+miBQMb /m H�M;�;2 Q`/BM�B`2 UB+B , Ŀ bB Ę �HQ`b · · · ŀV- [mB- iQmi �m HQM; /2 +2 +Qm`b-MQmb b2`p2Mi /2 Kûi�H�M;�;2 TQm` T�`H2` /2 MQi`2 H�M;�;2@Q#D2i L- H2 H�M;�;2 /2 H� HQ;B[m2T`QTQbBiBQMM2HH2XRk

RyX ZmǶBH 2tBbi2 +2ii2 TQbbB#BHBiû MQmb KQMi`2 [m2 H2 7`�MÏ�Bb 2bi mM2 H�M;m2 Ŀ bûK�MiB[m2K2Mi 72`Kû2 ŀ /�Mb H2b2Mb /2 h�`bFB- +Ƕ2bi@¨@/B`2 [mǶ2HH2 T2`K2i /2 T�`H2` /Ƕ2HH2@KāK2- 2M BM+Hm�Mi /2b MQKb TQm` +2b T`QT`2b 2tT`2bbBQMbXSQm` �+?2p2` b� +ûHĕ#`2 /û}MBiBQM /2 H� pû`Biû U+7X R8X9V 2i TQm` ûpBi2` H2 T�`�/Qt2 /m K2Mi2m` U+7X H� b+iX 9X9V-h�`bFB URNjj f RNdkV 2t+Hm�Bi H2b H�M;m2b bûK�MiB[m2K2Mi 72`Kû2b /2 +QMbB/û`�iBQM- /ûp2HQTT�Mi �BMbB H� MQiBQM/2 Ŀ H�M;m2 7Q`K2HH2 ŀX

RRX .�Mb H� H2ÏQM 8 U+7X TX RkkV MQmb p2``QMb [m2 Ŀ |4 ŀ MǶ2bi miBHBbû MQM b2mH2K2Mi TQm` T�`H2` /2 H� `2H�iBQM/2 +QMbû[m2M+2 HQ;B[m2- K�Bb �mbbB TQm` T�`H2` /2b i�miQHQ;B2b U/2b T?`�b2b [mB bQMi /2b +QMbû[m2M+2b HQ;B[m2b /2MǶBKTQ`i2 [m2HH2 T?`�b2VX

RkX Ŀ → ŀ- T�` +QMi`2- MǶ2bi T�b mM2 �#`ûpB�iBQM /2 Ŀ bB Ę �HQ`b · · · ŀ- K�Bb mM bB;M2 �miQMQK2 2i MQmp2�m- [mB2bi b2mH2K2Mi T`QMQM+û /2 H� KāK2 K�MBĕ`2X Ŀ 4⇒ ŀ- K�H;`û bQM �TT�`2M+2- MǶ2bi T�b mM2 2tT`2bbBQM /ǶmM H�M;�;27Q`K2H- K�Bb mM2 2tT`2bbBQM /m Kûi�H�M;�;2 BM7Q`K2H- +QKK2 HǶ2bi H2 Ŀ bbB ŀ miBHBbû 2M UjXd′V- [mB �TT�`iB2Mi �mKûi�@Kûi�H�M;�;2X

G� p�HB/Biû 2i H� pû`Biû HQ;B[m2 dR

LQmb TQmpQMb 7�B`2 mM2 /BbiBM+iBQM bBKBH�B`2 TQm` /Ƕ�mi`2b +QMM2+i2m`b T`QTQbBiBQMM2HbX Ŀ ∧ ŀ- QMHǶ� pm- 2tT`BK2 H� `2H�iBQM /2 +QMDQM+iBQM Ĝ +2 +QMM2+i2m` 7�Bi T�`iB2 /m H�M;�;2@Q#D2i /QMi MQmbûim/BQMb H2 +QKTQ`i2K2Mi HQ;B[m2X LQmb miBHBbQMb mM �mi`2 +QMM2+i2m`- Ŀ � ŀ- TQm` T�`H2` /2 +2H�M;�;2@Q#D2iX Ŀ � ŀ �TT�`iB2Mi T�` +QMbû[m2Mi �m Kûi�H�M;�;2X .2 KāK2 TQm` MQi`2 Mû;�iBQM/m H�M;�;2@Q#D2i- Ŀ ¬ ŀ- [mB +Q``2bTQM/ �m Kûi�H�M;�;2 ¨ Ŀ ∼ ŀ 2i H� /BbDQM+iBQM /m H�M;�;2Q#D2i Ŀ ∨ ŀ [mB +Q``2bTQM/ ¨ Ŀ || ŀX LQmb Q#i2MQMb ,

Ŀ ¬p ŀ 2bi p`�B bbB ∼ p

Ŀ p ∧ q ŀ 2bi p`�B bbB p � q

Ŀ p ∨ q ŀ 2bi p`�B bbB p || qĿ p→ q ŀ 2bi p`�B bbB p 4⇒ q

Ŀ p↔ q ŀ 2bi p`�B bbB p ⇐⇒ q

LQmb pQvQMb K�BMi2M�Mi [m2 H� +`�BMi2 /ǶmM +2`+H2 pB+B2mt- ûpQ[mû2 �m /û#mi /2 +2 +?�TBi`2-MǶûi�Bi T�b DmbiB}û2- KāK2 bǶBH v � T2mi@āi`2 mM +2`+H2 ûTBbiûKB[m2 /�Mb H2 b2Mb [m2 [m2H[mǶmM[mB M2 +QKT`2M/ T�b +2 [mǶ2bi H� Mû;�iBQM UM2 TQbbĕ/2 T�b H2 +QM+2Ti /2 Mû;�iBQMV M2 TQm``�BiMB +QKT`2M/`2 Ŀ ¬ ŀ- MB Ŀ ∼ ŀXRj

J�Bb BH MǶv � T�b /2 +2`+H2 pB+B2mt HQ;B[m2 , HǶ2tTHB+�iBQM [m2 MQmb �pQMb /QMMû2 /2 H� bB;MB}+�iBQM/2 H� Mû;�iBQM Ŀ ¬ ŀ M2 +QMi2M�Bi T�b H2 bB;M2 Ŀ ¬ ŀ [mǶQM ûi�Bi 2M i`�BM /Ƕ2tTHB[m2` U+2[mB +QMbiBim2`�Bi 2M 7�Bi mM +�b /2 +2`+H2 pB+B2mtVX LQmb 2tTHB[mQMb Ŀ ¬ ŀ 2M 2tTHQBi�Mi MQi`2+QKTûi2M+2 /�Mb mM H�M;�;2 /Bzû`2Mi Ĝ /m 7`�MÏ�Bb [mB MQmb b2`i /2 Kûi�H�M;�;2 Ĝ [mB TQm``�BiHmB@KāK2- bB QM 2M �p�Bi #2bQBM- āi`2 7Q`K�HBbû 2i û[mBTû /ǶmM2 bûK�MiB[m2 `B;Qm`2mb2 U+QKK2MQmb HǶ�pQMb 7�Bi �p2+ H2 H�M;�;2@Q#D2i- H2 H�M;�;2 /2 H� HQ;B[m2 /2b T?`�b2bVXR9

jXk G� p�HB/Biû 2i H� pû`Biû HQ;B[m2amTTQbQMb [mǶmM2 BM7û`2M+2 HQ;B[m2 �Bi H� 7Q`K2 bmBp�Mi2 ,

UjX3V pX 1i qX J�Bb �mbbB rX .QM+ sX

LQmb �pQMb pm [mǶQM T2mi K2ii`2 +2ii2 BM7û`2M+2 /�Mb H� 7Q`K2 bmBp�Mi2 ,

UjX3′Vpqrs

úi�Mi /QMMû H� bB;MB}+�iBQM /m +QMM2+i2m` Ŀ ∧ ŀ UĿ 2i ŀV- QM T2mi û;�H2K2Mi û+`B`2 HǶBM7û`2M+2UjX3′V +QKK2 bmBi ,

UjX3′′V p ∧ q ∧ rs

RjX G� `2K�`[m2 2Mi`2 T�`2Mi?ĕb2b M2 /2p`�Bi T�b āi`2 +QMbB/û`û +QKK2 û[mBp�H2Mi2 ¨ +2 [m2 H� T`2+ĕ/2X JāK2bǶBH v � bQmp2Mi- 2M T�`iB+mHB2` T�`KB H2b T?BHQbQT?2b �M�HviB[m2b 2M �HH2K�;M2 /�Mb H� /2mtBĕK2 KQBiBû /m kyĕK2bBĕ+H2- mM2 7Q`i2 i2M/�M+2 /ǶûpQ[m2` mM2 MQiBQM bm#bi�MiB2HH2 /2 Ŀ TQbb2bbBQM /2 +QM+2Ti ŀ- BH bǶ�;Bi /ǶmM +?QBti?ûQ`B[m2 7�+mHi�iB7 U+7X MQi`2 /Bb+mbbBQM /2 H� `2H�iBQM 2Mi`2 H� TQbb2bbBQM /m +QM+2Ti 2tT`BKû T�` Ŀ → ŀ 2i H�p�HB/Biû /2b BM7û`2M+2b /m ivT2 JS ¨ H� TX 3d 2i bmBp�Mi2bVX

R9X AH v �m`� mM2 ûi�T2 /�Mb H� `û;`2bbBQM /m H�M;�;2 Q#D2i �m Kûi�H�M;�;2 �mt Kûi�@Kûi�H�M;�;2b U2i �BMbB/2 bmBi2V Qɍ MQmb `2iQK#2`QMb /�Mb H2 H�M;�;2 Q`/BM�B`2X J�Bb +2+B M2 bB;MB}2 T�b [mǶBH bǶ�;Bi /ǶmM +2`+H2 pB+B2mt-TmBb[m2 +2 MǶ2bi T�b H� bB;MB}+�iBQM /2 H� Mû;�iBQM /m H�M;�;2 Q`/BM�B`2 [m2 MQmb pQmHQMb 2tTHB[m2` UK�Bb THmiƬi H�bB;MB}+�iBQM /2 Ŀ ¬ ŀ- mM bB;M2 /2 MQi`2 H�M;�;2 7Q`K2H LVX G2 7�Bi [m2 HǶQM TmBbb2 iQmDQm`b +QMiBMm2` ¨ /2K�M/2`Ŀ TQm`[mQB \ ŀ M2 bB;MB}2 T�b [mǶBH MǶv �Bi T�b /Ƕ2tTHB+�iBQMb U2MiBĕ`2K2MiV bm{b�Mi2b 2i �++2Ti�#H2bX

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dk jX _2H�iBQMb HQ;B[m2b 2i BM7û`2M+2b HQ;B[m2b

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UjXNV p→ ¬p¬p

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p ¬p p→ ¬pV F FF V V

p ¬pV FF V

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G� p�HB/Biû 2i H� pû`Biû HQ;B[m2 dj

p ¬p p→ ¬p (p→ ¬p)→ ¬pV F F VF V V V

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p |4 q ⇐⇒ |4 p→ q

§ /`QBi2 /2 +2ii2 û[mBp�H2M+2- MQmb miBHBbQMb Ŀ |4 ŀ TQm` /B`2 [m2 Ŀ p→ q ŀ 2bi mM2 i�miQHQ;B2-+Ƕ2bi@¨@/B`2 MǶ� T�b #2bQBM /2 T`ûKBbb2b TQm` āi`2 p�HB/2X PM T�`H2 �HQ`b /ǶĿ BKTHB+�iBQM 7Q`K2HH2 ŀ ,

BKTHB+�iBQM K�iû`B2HH2 /2 q T�` p ⇐⇒ Ŀ p→ q ŀ 2bi p`�BU Ŀ p b2mH2K2Mi bB q ŀV UbQBi Ŀ p ŀ 2bi 7�mt bQBi Ŀ q ŀ 2bi p`�BVBKTHB+�iBQM 7Q`K2HH2 /2 q T�` p ⇐⇒ Ŀ p→ q ŀ 2bi mM2 i�miQHQ;B2U Ŀ q ŀ 2bi mM2 +QMbû[m2M+2 bûK�MiB[m2 UBH MǶ2bi T�b HQ;B[m2K2Mi TQbbB#H2

/2 Ŀ p ŀV [m2 Ŀ p ŀ bQBi p`�B 2i Ŀ q ŀ 7�mtXV

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R8X AH M2 bǶ�;Bi T�b B+B /ǶmM2 /û}MBiBQM- K�Bb /ǶmM `ûbmHi�i bm#bi�MiB2H TQ`i�Mi bm` H� HQ;B[m2 T`QTQbBiBQMM2HH2-[m2 MQmb �TT2H2`QMb Ŀ i?ûQ`ĕK2 /2 /û/m+iBQM ŀ 2i T`Qmp2`QMb /�Mb H2 +?X dXkX

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RdX *Ƕ2bi TQm` +2ii2 `�BbQM [m2 H� +QMbû[m2M+2 HQ;B[m2 2bi û;�H2K2Mi �TT2HHû2 Ŀ +QMbû[m2M+2 HQ;B[m2 bûK�MiB[m2 ŀ-+2 [mB H� /BbiBM;m2 /2b Ŀ +QMbû[m2M+2b HQ;B[m2b bvMi�tB[m2b ŀ- [mB bQMi /2b `2H�iBQMb /2 /û/m+iB#BHBiû U/�Mb mM+2`i�BM +�H+mHV /QMi QM T�`H2`� THmb i�`/ /�Mb H� b+iX 9XRX

R3X CǶmiBHBb2 H2 bB;M2 Ŀ ! ŀ TQm` T�`H2` /m T`Q+2bbmb /2 7Q`K�HBb�iBQMX

Page 5: 2H iBQMbHQ;B[m2b2iBM7û`2M+2b HQ;B[m2bphilipp.philosophie.ch/handouts/logique19-logique3.pdf · TBi`2j _2H iBQMbHQ;B[m2b2iBM7û`2M+2b HQ;B[m2b jXRG2H M; ;2@Q#D2i2iH2Kûi H M; ;2 LQmb

d9 jX _2H�iBQMb HQ;B[m2b 2i BM7û`2M+2b HQ;B[m2b

Ŀ lM �`;mK2Mi /2 H� 7Q`K2

pqrs 2bi p�HB/2X ŀ ! Ŀ {p, q, r} |4 s ŀ

Ŀ lM �`;mK2Mi /2 H� 7Q`K2p ∧ q ∧ r

s 2bi p�HB/2X ŀ ! Ŀ {p ∧ q ∧ r} |4 s ŀ

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UjXRyV p |4 q

UjXRyV /ûbB;M2 H2 `ûbmHi�i /2 H� Dmti�TQbBiBQM /2 HǶ2tT`2bbBQM Ŀ AH bǶ2MbmBi /2 HǶ�{`K�iBQM [m2 ŀ-/2 H� T?`�b2 `2T`ûb2Miû2 T�` Ŀ p ŀ- /2 HǶ2tT`2bbBQM Ŀ [m2 ŀ 2i H� T?`�b2 `2T`ûb2Miû2 T�` Ŀ q ŀX aBĿ p ŀ `2T`ûb2Mi2 Ŀ �MM2 2bi �KQm`2mb2 /2 C2�M ŀ 2i [m2 Ŀ q ŀ `2T`ûb2Mi2 Ŀ �MM2 2bi �KQm`2mb2/2 [m2H[mǶmM ŀ- �HQ`b UjXRyV /2pB2Mi H� T?`�b2 bmBp�Mi2 ,

UjXRy′V AH bǶ2MbmBi /2 HǶ�{`K�iBQM [mǶ�MM2 2bi �KQm`2mb2 /2 C2�M [m2 �MM2 2bi �KQm`2mb2/2 [m2H[mǶmMX

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UjXRy′′V Ŀ p ŀ |4 Ŀ q ŀ

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UjXRRV φ ∧ ψ |4 φ

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G2 T`Q#HĕK2 �p2+ UjXRR′′V- +QKK2 �p2+ UjXRy′′V- 2bi [m2 MQmb �pQMb T2`/m H� ;ûMû`�HBiûX Ŀ φ∧ψ ŀMǶ2bi mM MQK [m2 TQm` +2ii2 2tT`2bbBQM T`û+Bb2 UH� H2ii`2 ;`2+[m2 Ŀ φ ŀ- bmBpB2 /2 Ŀ ∧ ŀ 2i /2 H�H2ii`2 ;`2+[m2 Ŀ ψ ŀVX *2T2M/�Mi- MQmb +?2`+?QMb mM2 K�MBĕ`2 /2 K2MiBQMM2` mM2 T?`�b2 p�`B�#H2�m b2BM /ǶmM2 7Q`K2 }t2X§ +2 T`QTQb- ZmBM2 � BMi`Q/mBi +2 [m2 MQmb �TT2HH2`QMb H� Ŀ [m�bB@+Bi�iBQM ŀ- [mB b2 7�Bi �p2+/2b /2KB@+`Q+?2ib- �TT2Hûb Ŀ /2KB@+`Q+?2ib /2 ZmBM2 ŀ UĿ ZmBM2 +Q`M2`b ŀVX LQmb biBTmHQMbbBKTH2K2Mi [m2 HǶ2tT`2bbBQM

UjXRkV "φ ∧ ψ#

/ûbB;M2`� H� 7Q`KmH2 [mB +QKK2M+2 �p2+ φ U+Ƕ2bi@¨@/B`2 H� T?`�b2 �`#Bi`�B`2 /ûMQiû2 T�` Ŀ φ ŀV-+QMiBMm2 �p2+ Ŀ ∧ ŀ 2i }MBi T�` ψX liBHBb2` H2b /2KB@+`Q+?2ib /2 ZmBM2 T2`K2i /QM+ /2 +`û2`mM MQK TQm` mM +2`i�BM ivT2 /2 T?`�b2b ¨ T�`iB` /Ƕ�mi`2b MQKb- +QKK2 /�Mb UjXRkV- Qɍ H2 MQKĿ "φ∧ψ# ŀ 2bi Q#i2Mm ¨ T�`iB` /2b MQKb Ŀ φ ŀ 2i Ŀ ψ ŀX UjXRkV MQmb T2`K2i /2 T�`H2` /2 iQmi2bH2b 2tT`2bbBQMb /2 MǶBKTQ`i2 [m2HH2 +QKTH2tBiû- �v�Mi mM2 +2`i�BM2 7Q`K2 U2M HǶQ++m``2M+2- mM27Q`K2 +QMDQM+iBp2VX .2 H� KāK2 K�MBĕ`2- "(µ)# /ûMQi2 H2 `ûbmHi�i /2 H� KBb2 2Mi`2 T�`2Mi?ĕb2b/2 HǶ2tT`2bbBQM µX 1M /Ƕ�mi`2b KQib- H� `�BbQM /Ƕāi`2 /2b /2KB@+`Q+?2ib /2 ZmBM2 +Ƕ2bi /2 MQmbT2`K2ii`2 /2b 2tT`2bbBQMb /m H�M;�;2 Q#D2i U Ŀ ∧ ŀ- Ŀ ( ŀ 2i Ŀ ) ŀ- T�` 2t2KTH2V ¨ HǶBMiû`B2m` /2b2tT`2bbBQMb /m Kûi�H�M;�;2XAH 2bi ¨ bQmHB;M2` [mǶBH bǶ�;Bi B+B /ǶmM2 bQHmiBQM �`iB}+B2HH2 ¨ mM T`Q#HĕK2 �`iB}+B2HX LQmb BMi`Q/mB@bQMb Ŀ ". . .# ŀ +QKK2 MQmp2HH2 2tT`2bbBQM /�Mb MQi`2 Kûi�H�M;�;2 2i biBTmHQMb b� bB;MB}+�iBQM ,k9

+2 b2`�Bi HǶ2tT`2bbBQM [mB K2i /2b ;mBHH2K2ib ǵQ`/BM�B`2bǶ �miQm` /2 HǶ2tT`2bbBQM . . .- K�Bb ǵQK2iǶUQm ǵ�MMmH2Ƕ- ǵ#Bz2ǶV iQmb H2b ;mBHH2K2ib ¨ HǶBMiû`B2m` /2 . . .X 1M pQB+B [m2H[m2b 2t2KTH2b ,

Ç LQmb miBHBbQMb Ŀ "φ∧ψ# ŀ TQm` T�`H2` /2 iQmi2b H2b T?`�b2b +QMDQM+iBp2b- T�` 2tX Ŀ p∧ q ŀ-Ŀ (p ∨ q) ∧ s ŀ- Ŀ p ∧ (q → s) ŀ 2i+X c

Ç LQmb miBHBbQMb Ŀ "φ→ ψ# ŀ TQm` T�`H2` /2 iQmi2b H2b BKTHB+�iBQMb K�iû`B2HH2b- [m2H[m2 bQBiH2m` +QKTH2tBiû c

Ç LQmb miBHBbQMb Ŀ "(φ)# ŀ TQm` T�`H2` /2 iQmi2b H2b 2tT`2bbBQMb [mB +QKK2M+2Mi �p2+ mM2T�`2Mi?ĕb2 ;�m+?2 2i }MBbb2Mi T�` mM2 T�`2Mi?ĕb2 ;�m+?2 c

Ç LQmb miBHBbQMb Ŀ " S�`Bb # ŀ TQm` T�`H2` /m MQK /2 H� pBHH2 /2 S�`Bb- +Ƕ2bi@¨@/B`2 TQm` T�`H2`/2 Ŀ S�`Bb ŀ c +Ƕ2bi /QM+ mM MQK /2 H� KāK2 2tT`2bbBQM [m2 ĿĿ S�`Bb ŀŀ 5

1M ;ûMû`�H- /2b K�i`B+2b +QKK2 T�` 2tX Ŀ ". . . ∧ · · ·# ŀ- Ŀ "(. . . )# ŀ 2i+X MQmb b2`p2Mi ¨ +QMbi`mB`2/2b MQKb +QKTH2t2b- +QKK2 H2 7QMi T�` 2t2KTH2 Ŀ H2 Tĕ`2 /2 Ę ŀ Qm Ŀ H� KQBiBû /2 Ę ŀX aB a�K2bi mM2 T2`bQMM2- �HQ`b Ŀ H2 Tĕ`2 /2 a�K ŀ /ûMQi2 H2 Tĕ`2 /2 +2ii2 T2`bQMM2X aB a 2bi mM +2`i�BMMQK#`2- �HQ`b Ŀ H� KQBiBû /2 a ŀ /ûMQi2 H� KQBiBû /2 +2 MQK#`2Xk8 aB φ 2bi mM2 +2`i�BM2 T?`�b2-�HQ`b "(φ)# /ûMQi2 H2 `ûbmHi�i /2 H� KBb2 2Mi`2 T�`2Mi?ĕb2b /2 +2ii2 T?`�b2X aB φ 2bi Ŀ a�K 2bii`Bbi2 ŀ- �HQ`b "(φ)# 2bi HǶ2tT`2bbBQM ĿUa�K 2bi i`Bbi2VŀX aB φ 2bi Ŀ a�K � 7�BK ŀ 2i ψ 2bi Ŀ J�`B2p2mi b2 K�`B2` ŀ- �HQ`b "φ ∧ ψ# /2pB2Mi Ŀ a�K � 7�BK 2i J�`B2 p2mi b2 K�`B2` ŀ UH2 MQK /2 H�T?`�b2 +QMDQM+iBp2VX LQmb TQmpQMb- #B2M bȿ`- bm#biBim2` +2 [m2 /ûbB;M2 φ T�` H� T?`�b2 Ŀ p ŀ 2i+2 [mB /ûbB;M2 ψ T�` H� T?`�b2 Ŀ q ŀ- Q#i2M�Mi �HQ`b ¨ T�`iB` /2 UjXRkV HǶ2tT`2bbBQM bmBp�Mi2 ,

UjXRk′V Ŀ p ∧ q ŀ

UjXRk′V 2bi mM MQK /2 H� +QMDQM+iBQM /2b /2mt T?`�b2b bBKTH2b- +QM+`ĕi2b- [mB T�`H2Mi T�` 2t2KTH2/2 H� HQ;B[m2 2i /m #QM?2m`X aB MQmb �#`û;2QMb T�` Ŀ s ŀ H� T?`�b2 Ŀ H2 bQH2BH #`BHH2 ŀ- �HQ`bĿ p ∧ (q ∧ s) ŀ 2bi mM2 �mi`2 BMbi�M+2 /2 UjXRkV- [mB T�`H2 /m bQH2BH- /2 H� HQ;B[m2 2i /m #QM?2m`X

k9X .2 H� KāK2 K�MBĕ`2- D2 TQm``�Bb BMi`Q/mB`2 mM ivT2 /2 ǵ+Bi�iBQMǶ Ŀ ∗ . . . ∗ ŀ 2i HmB /QMM2` H� bB;MB}+�iBQMĿ H� T?`�b2 [mB 2bi H� K2BHH2m`2 `ûTQMb2 ¨ Ŀ Ę ŀ ŀX �BMbB- HǶ2tT`2bbBQM Ŀ ∗ [m2H 2bi H2 b2Mb /2 H� pB2 \ ∗ ŀ b2`�Bi mMMQK TQm` HǶ2tT`2bbBQM Ŀ 9k 5 ŀ UTQm` 2M b�pQB` THmb- +QMbmHi2x G2 :mB/2 /m pQv�;2m` ;�H�+iB[m2VX

k8X LQmb `2iQm`M2`QMb- /�Mb H� b+iX RyXR- ¨ +2b MQKb +QKTH2t2b [mǶQM �TT2HH2`� Ŀ 7QM+iBQMb ŀX

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d3 jX _2H�iBQMb HQ;B[m2b 2i BM7û`2M+2b HQ;B[m2b

*QMi`�B`2K2Mi ¨ +2ii2 bTû+B}+Biû /m H�M;�;2@Q#D2i- MQmb TQmpQMb +QM+2pQB` UjXRkV +QKK2 H2 MQK/ǶmM2 T?`�b2 +QMi2M�Mi /2b H�+mM2b Ŀ Ę ∧ · · · ŀ- Qɍ H� T`2KBĕ`2 H�+mM2 U`2T`ûb2Miû2 T�` H2b TQBMib/2 bmbT2MbBQM Ŀ . . . ŀV 2bi `2KTHB2 T�` H� /ûbB;M�iBQM /m MQK φ 2i H� /2mtBĕK2 H�+mM2 U`2T`ûb2Miû2T�` Ŀ · · · ŀV 2bi `2KTHB2 T�` UH� /ûbB;M�iBQM /m MQKV ψX GǶ�p�Mi�;2 /Ƕ�pQB` /2b MQKb TQm` /2bT?`�b2b MQM@bTû+B}û2b 2bi [m2 φ 2i ψ T2mp2Mi āi`2 /2 MǶBKTQ`i2 [m2HH2 +QKTH2tBiû , /�Mb UjXRkV-MQmb TQmpQMb �mbbB bm#biBim2` φ T�` Ŀ p → q ŀ 2i ψ T�` Ŀ (p ∨ q) ∧ r ŀX GǶ�p�Mi�;2 /2b /2KB@+`Q+?2ib M2 +QM+2`M2 [m2 H2b MQKb +QKTH2t2b , 2M HǶ�#b2M+2 /2 +QMM2+i2m`b- H2b /2KB@+`Q+?2ibMǶQMi T�b /Ƕ2z2i �mi`2 [m2 H2b ;mBHH2K2ib Q`/BM�B`2bX "φ# 2bi bBKTH2K2Mi φX G2m` miBHBiû `ûbB/2/�Mb H2 7�Bi [mǶ2HH2b MQmb T2`K2ii2Mi /ǶmiBHBb2` /2b +QMM2+i2m`b /m H�M;�;2@Q#D2i TQm` bTû+B}2` H�7Q`K2 HQ;B[m2 /2b T?`�b2b [m2 MQmb pQmHQMb K2MiBQMM2`X *Ƕ2bi �p2+ +2b /2KB@+`Q+?2ib [m2 MQmbT�`p2MQMb }M�H2K2Mi ¨ mM2 7Q`KmH�iBQM b�iBb7�Bb�Mi2 /2 UjXRRV ,

UjXRR′′′V "φ ∧ ψ# |4 φ

GǶ2tT`2bbBQM UjXRR′′′V /ûbB;M2 H2 `ûbmHi�i /2 H� Dmti�TQbBiBQM /2 HǶ2tT`2bbBQM Ŀ úi�Mi /QMMû HǶ�7@}`K�iBQM [m2 ŀ- /2 MǶBKTQ`i2 [mǶ2HH2 T?`�b2 /ûbB;Mû2 T�` φ- /m +QMM2+i2m` Ŀ ∧ ŀ- /2 MǶBKTQ`i2[m2HH2 T?`�b2 /ûbB;Mû2 T�` ψ- /2 HǶ2tT`2bbBQM Ŀ BH bǶ2MbmBi [m2 ŀ 2i /2 H� T?`�b2 /ûbB;Mû2 T�` φXS2m BKTQ`i2 [m2HH2 bQBi H� T?`�b2 φ- 2HH2 bǶ2MbmBi /2 MǶBKTQ`i2 [m2HH2 +QMDQM+iBQM /QMi 2HH2 7�BiT�`iB2X aB φ /ûbB;M2 Ŀ a�K � 7�BK ŀ 2i ψ /ûbB;M2 Ŀ J�`B2 p2mi b2 K�`B2` ŀ- �HQ`b UjXRR′′′V /2pB2MiH� T?`�b2 bmBp�Mi2 ,

UjXRR′′′′V úi�Mi /QMMû [m2 a�K � 7�BK 2i [m2 J�`B2 p2mi b2 K�`B2`- BH bǶ2MbmBi [m2 a�K �7�BKX

*Ƕ2bi +2i mb�;2 [m2 MQmb �/QTi2`QMb T�` H� bmBi2X

jX9 G2b i�miQHQ;B2b 2i H2b +QMi`�/B+iBQMblM2 BM7û`2M+2 HQ;B[m2 2bi p�HB/2 bB 2i b2mH2K2Mi bǶBH MǶ2bi T�b HQ;B[m2K2Mi TQbbB#H2 [m2 b2b T`û@KBbb2b bQB2Mi p`�B2b 2i b� +QM+HmbBQM 7�mbb2- +Ƕ2bi@¨@/B`2 bB iQmi2 �ii`B#miBQM /2 p�H2m`b /2 pû`Biû ¨b2b +QMbiBim�Mib bBKTH2b [mB `2M/ p`�B2b H2b T`ûKBbb2b `2M/ û;�H2K2Mi p`�B2 H� +QM+HmbBQMX úi�Mi/QMMû H� bB;MB}+�iBQM /2 HǶBKTHB+�iBQM K�iû`B2HH2 Ŀ → ŀ Ĝ [mǶ2HH2 2bi p`�B2 bǶBH MǶ2bi T�b H2 +�b[m2 HǶ�Miû+û/2Mi 2bi p`�B 2i H2 +QMbû[m2Mi 7�mt Ĝ mM2 BM7û`2M+2 [mB � Ŀ p ŀ +QKK2 T`ûKBbb2 2iĿ q ŀ +QKK2 +QM+HmbBQM 2bi p�HB/2 bB 2i b2mH2K2Mi bB Ŀ p→ q ŀ 2bi mM2 i�miQHQ;B2XlM2 T?`�b2 2bi mM2 i�miQHQ;B2 bB 2i b2mH2K2Mi bB 2HH2 2bi p`�B2 /�Mb iQmi2b H2b TQbbB#BHBiûb HQ;B[m2b-+Ƕ2bi@¨@/B`2 p`�B2 bQmb iQmi2b H2b �ii`B#miBQMb /2 p�H2m`b /2 pû`Biû ¨ b2b +QMbiBim�Mib bBKTH2bX*Ƕ2bi TQm` +2ii2 `�BbQM [m2 H2b i�miQHQ;B2b bQMi �TT2Hû2b Ŀ pû`Biûb HQ;B[m2b ŀX G� Mû;�iBQM /ǶmM2i�miQHQ;B2- ûi�Mi /QMMû H� bB;MB}+�iBQM /2 Ŀ ¬ ŀ- 2bi mM2 T?`�b2 7�mbb2 /�Mb iQmi2b H2b TQbbB#BHBiûbHQ;B[m2b Ĝ BH MǶv � �m+mM2 �ii`B#miBQM /2 p�H2m`b /2 pû`Biû ¨ b2b +QMbiBim�Mib bBKTH2b [mB H� `2M/2p`�B2X PM �TT2HH2 +2b 7�mbb2iûb HQ;B[m2b /2b Ŀ +QMi`�/B+iBQMb ŀXke

keX LQmb �pQMb /ûD¨ `2M+QMi`û H2b i�miQHQ;B2b 2i H2b +QMi`�/B+iBQMb /�Mb H2b +QHQMM2b R 2i Re /m i�#H2�m /2bRe +QMM2+i2m`b #BM�B`2b TQbbB#H2b U+7X TTX 8N 2i eRVX 1HH2b +Q``2bTQM/2Mi ¨ /2b Ŀ 7QM+iBQMb /2 pû`Biû ŀ UĿ i`mi?@7mM+iBQMb ŀV /�Mb H2 KāK2 b2Mb [mǶmM2 7QM+iBQM +QMbi�Mi2 T2mi āi`2 �TT2Hû2 Ŀ mM2 7QM+iBQM ŀX _B2M M2 MQmb2KTā+?2 /ǶBMi`Q/mB`2 /2b +QMM2+i2m`b Ŀ ⊤ ŀ 2i Ŀ ⊥ ŀ �p2+ H2b i�#H2b /2 pû`Biû bmBp�Mi2b ,

p q p⊤qV V VV F VF V VF F V

p q p⊥qV V FV F FF V FF F F

*QKK2 H2b p�H2m`b /2 pû`Biû /2 Ŀ p⊤q ŀ 2i /2 Ŀ p⊥q ŀ M2 /ûT2M/2Mi T�b /2b p�H2m`b /2 pû`Biû /2 Ŀ p ŀ 2i /2Ŀ q ŀ- mM2 i2HH2 biBTmH�iBQM � T2m /ǶBMiû`āi U+7X �mbbB\- RjeVX 1HH2 T`ûb2Mi2 û;�H2K2Mi HǶBM+QMpûMB2Mi /Ƕāi`2 2M +QM~Bi

G2b i�miQHQ;B2b 2i H2b +QMi`�/B+iBQMb dN

AH bǶ2MbmBi /2 H2m`b /û}MBiBQMb [m2 H2b i�miQHQ;B2b 2i H2b +QMi`�/B+iBQMb DQm2Mi mM `ƬH2 T�`iB+mHB2`/�Mb H2b BM7û`2M+2b , mM2 i�miQHQ;B2- TmBb[mǶ2HH2 M2 T2mi T�b āi`2 7�mbb2- T2mi āi`2 BM7û`û2 /2MǶBKTQ`i2 [m2HH2 T`ûKBbb2Xkd Zm2H[m2b bQB2Mi H2b T`ûKBbb2b /QMi QM BM7ĕ`2 H� i�miQHQ;B2- BH MǶ2biT�b HQ;B[m2K2Mi TQbbB#H2 [m2 +2b T`ûKBbb2b bQB2Mi p`�B2b 2i H� i�miQHQ;B2 7�mbb2X lM2 i�miQHQ;B2T2mi KāK2 āi`2 BM7û`û2 /ǶmM 2Mb2K#H2 pB/2 /2 T`ûKBbb2bX lM2 +QMi`�/B+iBQM- �m +QMi`�B`2- 2bi mM2T`ûKBbb2 /QMi QM T2mi BM7û`2` MǶBKTQ`i2 [m2HH2 +QM+HmbBQMX Zm2HH2 [m2 bQBi H� +QM+HmbBQM [mǶQMp2mi 2M iB`2`- BH MǶ2bi T�b HQ;B[m2K2Mi TQbbB#H2 [m2 H� T`ûKBbb2 UH� +QMi`�/B+iBQMV bQBi p`�B2 2i [m2H� +QM+HmbBQM bQBi 7�mbb2XlM2 i�miQHQ;B2 T�`�/B;K�iB[m2 2bi H� T?`�b2 Ŀ p ∨ ¬p ŀXk3 Ŀ p ∧ ¬p ŀ 2bi mM2 +QMi`�/B+iBQM2t2KTH�B`2X a2HQM H2b +QMbB/û`�iBQMb T`û+û/2Mi2b- QM pQBi [m2 H2b BM7û`2M+2b

qp ∨ ¬p

¬(p ∨ ¬p)q

p ∧ ¬pq

q

¬(p ∧ ¬p)

bQMi p�HB/2b- [m2HH2 [m2 bQBi H� T?`�b2 /ûbB;Mû2 T�` Ŀ q ŀ , QM T2mi BM7û`2` mM2 i�miQHQ;B2 /2 MǶBK@TQ`i2 [m2HH2 T?`�b2 2i QM T2mi BM7û`2` MǶBKTQ`i2 [m2HH2 T?`�b2 /ǶmM2 +QMi`�/B+iBQMX SmBb[mǶmM2i�miQHQ;B2 bǶ2MbmBi /2 MǶBKTQ`i2 [m2HH2 T`ûKBbb2- QM T2mi /B`2 /2 H� K�MBĕ`2 bmBp�Mi2 [m2 Ŀ p∨¬p ŀ2bi mM2 i�miQHQ;B2 ,

UjXRjV |4 p ∨ ¬p

*2+B bǶ�++Q`/2 �p2+ MQi`2 2tTHB+�iBQM /2 H� +QMbû[m2M+2 HQ;B[m2 , H� T?`�b2 Ŀ φ |4 ψ ŀ 2bi p`�B2bB 2i b2mH2K2Mi bǶBH 2bi p`�B TQm` MǶBKTQ`i2 [m2Hb φ 2i ψ [m2 , bB φ 2bi p`�B- �HQ`b ψ HǶ2bi �mbbBXaǶBH 2bi BKTQbbB#H2 iQmi +Qm`i [m2 ψ bQBi 7�mbb2- �HQ`b +2ii2 +QM/BiBQM 2bi iQmDQm`b `2KTHB2 , TQm`MǶBKTQ`i2 [m2H T?`�b2 Ŀ p ŀ- H� /BbDQM+iBQM Ŀ p∨¬p ŀ2bi p`�B2 Ĝ 2HH2 2bi mM2 +QMbû[m2M+2 HQ;B[m2/2 HǶ2Mb2K#H2 pB/2 /2 T`ûKBbb2bXSQm` /B`2 [m2 Ŀ p ∧ ¬p ŀ 2bi mM2 +QMi`�/B+iBQM- QM T2mi �{`K2` ,

UjXR9V |4 ¬(p ∧ ¬p)

UjXR9V /Bi [m2 Ŀ ¬(p ∧ ¬p) ŀ 2bi mM2 i�miQHQ;B2 2i �HQ`b b� Mû;�iBQM 2bi mM2 +QMi`�/B+iBQMXaB /2mt T?`�b2b +QKTH2t2b QMi H� KāK2 i�#H2 /2 pû`Biû- BH MǶv � �m+mM2 `�BbQM HQ;B[m2 /2 H2b/BbiBM;m2` , 2M +2 [mB +QM+2`M2 mM2 HQ;B[m2 2ti2MbBQMM2HH2- 2HH2b /Bb2Mi H� KāK2 +?Qb2XkN 1Mi`2H2b /2mt- BH bǶ�;Bi /Ƕû[mBp�H2M+2 HQ;B[m2X G� `2H�iBQM 2Mi`2 H� MQiBQM /ǶĿ û[mBp�H2M+2 HQ;B[m2 ŀ /mKûi�H�M;�;2 2i HǶû[mBp�H2M+2 K�iû`B2HH2 /m H�M;�;2@Q#D2i 2bi H� KāK2 [m2 +2HH2 2Mi`2 H� MQiBQM /2Ŀ +QMbû[m2M+2 HQ;B[m2 ŀ 2i HǶBKTHB+�iBQM K�iû`B2HH2X .B`2 [m2 p→ q- `2pB2Mi ¨ /B`2 [mǶBH MǶ2bi T�bH2 +�b [m2 Ŀ p ŀ 2bi p`�B 2i Ŀ q ŀ 7�mtX .B`2 [m2 ψ 2bi mM2 +QMbû[m2M+2 HQ;B[m2 /2 φ `2pB2Mi ¨ /B`2[mǶBH MǶv � �m+mM +�b U�m+mM2 TQbbB#BHBiû HQ;B[m2V Qɍ φ 2bi p`�B 2i ψ 7�mtX .B`2 [m2 p↔ q- `2pB2Mi

�p2+ mM �mi`2 mb�;2 /2 Ŀ ⊤ ŀ 2i /2 Ŀ ⊥ ŀ- BMi`Q/mBi ¨ H� TX 8y U+7X MX kNV- +QKK2 H2ii`2b b+?ûK�iB[m2b TQm` /2bi�miQHQ;B2b 2i +QMi`�/B+iBQMb �`#Bi`�B`2bX

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k3X *QKT�`2x +2ii2 T?`�b2 �p2+ Ŀ hQmi2 T?`�b2 "φ ∨ ¬φ# 2bi mM2 i�miQHQ;B2X ŀ .�Mb Ŀ lM2 i�miQHQ;B2 T�`�/B;@K�iB[m2 2bi H� T?`�b2 Ŀ p ∨ ¬p ŀ ŀ- QM T�`H2 /ǶmM2 T?`�b2 T`û+Bb2- T�` 2t2KTH2 /2 Ŀ BH TH2mi Qm BH M2 TH2mi T�b ŀX.�Mb Ŀ hQmi2 T?`�b2 "φ ∨ ¬φ# 2bi mM2 i�miQHQ;B2 ŀ QM T�`H2 /2 iQmi2b H2b T?`�b2b [mB QMi mM2 +2`i�BM2 7Q`K2-+Ƕ2bi@¨@/B`2 /2 +2HH2b [mB bQMi +QKTQbû2b /ǶmM2 T?`�b2- /ǶmM2 2tT`2bbBQM TQm` H� /BbDQM+iBQM 2i /2 H� Mû;�iBQM /2+2ii2 T?`�b2X *Ƕ2bi H� `�BbQM TQm` H�[m2HH2 QM miBHBb2 H2b /2KB@+`Q+?2ib /2 ZmBM2 /�Mb +2 +�bX

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3y jX _2H�iBQMb HQ;B[m2b 2i BM7û`2M+2b HQ;B[m2b

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¬(p ∧ q) ⇐⇒ ¬p ∨ ¬q¬(p ∨ q) ⇐⇒ ¬p ∧ ¬q

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UjXR8V "¬(φ ∧ ψ)# ⇐⇒ "¬φ ∨ ¬ψ#"¬(φ ∨ ψ)# ⇐⇒ "¬φ ∧ ¬ψ#

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G2b i�miQHQ;B2b 2i H2b +QMi`�/B+iBQMb 3R

Mû;�iBQMb /2p�Mi /2b +QMDQM+iBQMb 2i /2b /BbDQM+iBQMb ¨ HǶBMiû`B2m` /2 +2b 7Q`KmH2b- 2M û+?�M;2�MiH2 +QMM2+i2m` Ŀ ∧ ŀ Qm Ŀ ∨ ŀ �p2+ bQM +QMM2+i2m` Ł QTTQbû ł Ŀ ∨ ŀ Qm Ŀ ∧ ŀXjj

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UjXReV "φ→ ψ# :⇐⇒ "¬φ ∨ ψ#

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jX aB QM M2 T`2M�Bi [m2 Ŀ ¬ ŀ 2i Ŀ→ ŀ +QKK2 T`BKBiB7b U+QKK2 6`2;2 UR3dNV 2i ƇmF�bB2rB+xURNy9VV- QM TQm``�Bi /û}MB` H2b �mi`2b +QKK2 bmBi ,"φ ∧ ψ# :⇐⇒ "¬(φ→ ¬ψ)#"φ ∨ ψ# :⇐⇒ "¬φ→ ψ#"φ↔ ψ# ⇐⇒ "(φ→ ψ) ∧ (ψ → φ)# :⇐⇒ "¬((φ→ ψ)→ ¬(ψ → φ))#

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jjX LQmb /QMM2`QMb THmb i�`/ U¨ H� TX RjyV mM2 bB;MB}+�iBQM THmb 2t�+i2 ¨ +2 i2`K2 Ŀ QTTQbû ŀ- [mB 2bi B+B miBHBbû2/�Mb mM b2Mb BM7Q`K2HX

j9X GQ`b[m2 H� /û}MBiBQM 2bi #�bû2 bm` mM2 B/2MiBiû THmiƬi [m2 bm` mM2 û[m�iBQM- MQmb �DQmiQMb H2b /2mt TQBMib�m bB;M2 /ǶB/2MiBiû , Ŀ .û}MBbbQMb Ŀ a ŀ +QKK2 bmBi , a :=

√b Ę ŀX lM T`Q#HĕK2 �//BiBQMM2H- 2i BKTQ`i�Mi-

/�Mb H2 +�b /2b /û}MBiBQMb #�bû2b bm` /2b B/2MiBiûb 2bi H� MQM@2tBbi2M+2 TQbbB#H2 /2 H� +?Qb2 2M [m2biBQMX LQmb`2iQm`M2`QMb ¨ +2b T`Q#HĕK2b /�Mb H2 +QMi2ti2 /2 /2b+`BTiBQMb /û}MB2b ¨ H� TX kjkX§ H� TH�+2 /2b /2mt TQBMib- QM miBHBb2 �mbbB Ŀ /û7X ŀ +QKK2 BM/2t ,

"φ→ ψ# /û7X←→ "¬φ ∨ ψ# 2i a /û7X=√b

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3k jX _2H�iBQMb HQ;B[m2b 2i BM7û`2M+2b HQ;B[m2b

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UjXRdV "φ ∧ ψ# ⇐⇒ "ψ ∧ φ#"φ ∨ ψ# ⇐⇒ "ψ ∨ φ#

lM2 �mi`2 ǵHQBǶ Uû[mBp�H2M+2 HQ;B[m2 ;ûMû`�H2Vj8 MQmb T2`K2i /2 /Bbi`B#m2` H� +QMDQM+iBQM bm` mM2/BbDQM+iBQM 2i pB+2 p2`b� ,

UjXR3V "φ ∨ (ψ ∧ χ)# ⇐⇒ "(φ ∨ ψ) ∧ (φ ∨ χ)#"φ ∧ (ψ ∨ χ)# ⇐⇒ "(φ ∧ ψ) ∨ (φ ∧ χ)#

LQmb �TT2H2`QMb UjXR3V H� Ŀ HQB /2 /Bbi`B#miBpBiû ŀX *2ii2 HQB- +QKK2 bQM û[mBp�H2Mi 2M �H;ĕ#`2Ŀ x(y + z + . . . + w) = xy + xz + . . . + xw ŀ-je MQmb T2`K2i /2 Ł 7�+iQ`Bb2` ł- +Ƕ2bi@¨@/B`2 /2i`�Mb7Q`K2`

(p ∨ t) ∧ (q ∨ r ∨ s)

2M

(p ∧ q) ∨ (p ∧ r) ∨ (p ∧ s) ∨ (t ∧ q) ∨ (t ∧ r) ∨ (t ∧ s)

úi�Mi /QMMû +2 [m2 MQmb �pQMb /Bi /2b i�miQHQ;B2b 2i /2b +QMi`�/B+iBQMb- BH 2bi iQmDQm`b TQbbB#H2/ǶQK2ii`2 mM2 i�miQHQ;B2 [mB �TT�`�ŗi ¨ HǶBMiû`B2m` /ǶmM2 +QMDQM+iBQM 2i mM2 +QMi`�/B+iBQM ¨HǶBMiû`B2m` /ǶmM2 /BbDQM+iBQM ,

UjXRNV "φ ∧ (ψ ∨ ¬ψ)# ⇐⇒ φ"φ ∨ (ψ ∧ ¬ψ)# ⇐⇒ φ

.Ƕ�mi`2b bBKTHB}+�iBQMb bQMi `2M/m2b TQbbB#H2b T�` H2 7�Bi [m2 φ 2bi û[mBp�H2Mi ¨ iQmi2b H2b T?`�b2bbmBp�Mi2b ,

UjXkyV "¬¬φ# , "φ ∧ φ# , "φ ∨ φ# , "φ ∨ (φ ∧ ψ)# , "φ ∧ (φ ∨ ψ)# , "(φ ∧ ψ) ∨ (φ ∧¬ψ)# , "(φ ∨ ψ) ∧ (φ ∨ ¬ψ)#

*2ii2 /2`MBĕ`2 Q#b2`p�iBQM /QMM2 /2 H� bm#bi�M+2 ¨ MQi`2 �{`K�iBQM U7�Bi2 ¨ H� TX k3V [m2 bB mM2H�M;m2 +QMiB2Mi mM2 T?`�b2 2i mM /2 +2b +QMM2+i2m`b- �HQ`b 2HH2 +QMiB2Mi �miQK�iB[m2K2Mi mM2BM}MBiû /2 T?`�b2bXGǶû[mBp�H2M+2 HQ;B[m2- KāK2 bB 2HH2 2bi /ǶmM2 miBHBiû T�`iB+mHBĕ`2 TQm` H� i`�Mb7Q`K�iBQM /2 7Q`@KmH2b- MǶ2bi [mǶmM2 b2mH2 /2 iQmi2 mM2 7�KBHH2 /2 `2H�iBQMb bûK�MiB[m2bX

j8X C2 K2ib Ŀ HQB ŀ 2M ǵb+�`2 [mQi2bǶ TmBb[mǶBH bǶ�;Bi iQmi bBKTH2K2Mi /ǶmM2 û[mBp�H2M+2 HQ;B[m2- i�miQHQ;B[m2;`�+2 ¨ H� bûK�MiB[m2 2i T`Qmp�#H2 ;`�+2 ¨ H� bvMi�t2 /2 H� HQ;B[m2 T`QTQbBiBQMM2HH2X S�`H2` /2 ǵHQBbǶ ûpQ[m2 HǶBK�;2/2 ǵHQBb /2 H� T2Mbû2Ƕ /QMi BH MǶ2bi T�b [m2biBQM B+BX G� /BbiBM+iBQM 2Mi`2 �tBQK2b 2i i?ûQ`ĕK2b- [m2 MQmb BMi`Q/mBbQMb/�Mb H2 +?�TBi`2 T`Q+?�BM `2M/`� +2b MQiBQMb BMimBiBp2b #2�m+QmT THmb +H�B`2bX

jeX *2ii2 Ł û[mBp�H2M+2 ł T2mi āi`2 `2M/m THmb +H�B` U2i KQBMb Kûi�T?Q`B[m2V ¨ HǶ�B/2 /2b �H;ĕ#`2b /2 "QQH2-+QKK2 QM H2 p2``� /�Mb H2 +?X dXe

G2 +�``û /2b QTTQbBiBQMb 3j

jX8 G2 +�``û /2b QTTQbBiBQMbPM /Bi bQmp2Mi /ǶmM2 +QMi`�/B+iBQM [mǶ2HH2 2bi +QMi`�/B+iQB`2 �p2+ 2HH2@KāK2 Qm [mǶ2HH2 b2 +QMi`2/Bi2HH2@KāK2X LQmb �pQMb B+B mM2 `2H�iBQM /m KāK2 MBp2�m [m2 H� +QMbû[m2M+2 HQ;B[m2 , H� `2H�iBQM/2 +QMi`�/B+iBQM �TT�`iB2Mi �mbbB �m Kûi�H�M;�;2X .2mt T?`�b2b bQMi +QMi`�/B+iQB`2b bB 2HH2b M2T2mp2Mi T�b āi`2 p`�B2b 2Mb2K#H2 2i M2 T2mp2Mi T�b āi`2 7�mbb2b 2Mb2K#H2 c mM2 b2mH2 /Ƕ2Mi`2 2HH2b/QBi āi`2 p`�B2- TmBb[m2 H� pû`Biû /2 H� T`2KBĕ`2 2Mi`�ŗM2 H� 7�mbb2iû /2 H� /2mtBĕK2 2i H� 7�mbb2iû/2 H� /2mtBĕK2 2Mi`�ŗM2 H� pû`Biû /2 H� T`2KBĕ`2Xjd

G2 /2`MB2` +QMDQBMi 2bi BKTQ`i�Mi , āi`2 +QMi`�/B+iQB`2 MǶ2bi T�b H� b2mH2 K�MBĕ`2 /Ƕāi`2 BM+QKT�@iB#H2 TQm` /2b T?`�b2bX *QKT�`QMb H2b /2mt T�B`2b /2 T?`�b2b bmBp�Mi2b ,

UjXkRV Ŀ G� HQ;B[m2 K2 `2M/ ?2m`2mb2X ŀ 2i Ŀ G� HQ;B[m2 M2 K2 `2M/ T�b ?2m`2mb2X ŀ

UjXkkV Ŀ G� HQ;B[m2 K2 `2M/ ?2m`2mb2X ŀ 2i Ŀ G� HQ;B[m2 K2 `2M/ K�H?2m`2mb2X ŀ

.�Mb H2b /2mt +�b- BH 2bi BKTQbbB#H2 [m2 H2b /2mt T?`�b2b bQB2Mi p`�B2b U2M KāK2 i2KTb- TQm` H�KāK2 T2`bQMM2VX J�Bb BH v � mM2 /Bzû`2M+2 ,

RX .�Mb H2 T`2KB2` +�b UjXkRV- QM T2mi +QM+Hm`2 H� pû`Biû /2 H� /2mtBĕK2 T?`�b2 T�` H� 7�mbb2iû/2 H� T`2KBĕ`2X

kX .�Mb H2 /2mtBĕK2 +�b UjXkkV- QM M2 H2 T2mi T�b , H2b /2mt T?`�b2b TQm``�B2Mi āi`2 7�mbb2b-T�` 2t2KTH2 /�Mb H2 +�b Qɍ H� HQ;B[m2 K2 H�Bbb2 BM/Bzû`2Mi2X

G2b T?`�b2b /2 H� T`2KBĕ`2 T�B`2 M2 T2mp2Mi MB āi`2 p`�B2b 2Mb2K#H2b MB āi`2 7�mbb2b 2Mb2K#H2b cH2b T?`�b2b /2 H� /2mtBĕK2 T�B`2 M2 T2mp2Mi T�b āi`2 p`�B2b 2Mb2K#H2- K�Bb 2HH2b T2mp2Mi āi`27�mbb2b 2Mb2K#H2XaB /2mt T?`�b2b bQMi `2HBû2b /2 H� KāK2 K�MBĕ`2 [m2 UjXkRV- +Ƕ2bi@¨@/B`2 /2 i2HH2 K�MBĕ`2 [mǶQMTmBbb2 +QM+Hm`2 H� pû`Biû /2 HǶmM2 T�` H� 7�mbb2iû /2 HǶ�mi`2 2i H� 7�mbb2iû /2 HǶ�mi`2 T�` H� pû`Biû/2 H� T`2KBĕ`2- QM H2b �TT2HH2 Ŀ +QMi`�/B+iQB`2b ŀX aB H2b /2mt T?`�b2b bQMi `2HBû2b /2 H� KāK2K�MBĕ`2 [m2 UjXkkV- BH 2bi TQbbB#H2 /2 /û/mB`2 H� 7�mbb2iû /2 HǶmM2 ¨ T�`iB` /2 HǶ�mi`2- K�Bb HǶBMp2`b2MǶ2bi T�b p`�B , MQmb M2 TQmpQMb T�b /û/mB`2 H� pû`Biû /2 HǶmM2 T�` H� 7�mbb2iû /2 HǶ�mi`2X *2bûMQM+ûb bQMi �BMbB [m�HB}ûb /2 Ŀ +QMi`�B`2b ŀX .Ƕ�mi`2b 2t2KTH2b /2 T?`�b2b +QMi`�B`2b UK�Bb T�b+QMi`�/B+iQB`2bV bQMi H2b T�B`2b bmBp�Mi2b ,

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jdX CǶmiBHBb2 Ŀ 2Mi`�ŗM2 ŀ B+B TQm` /ûbB;M2` H� `2H�iBQM /2 +QMbû[m2M+2 HQ;B[m2- û;�H2K2Mi /ûbB;Mû2 T�` Ŀ |4 ŀX

j3X lM 2t2KTH2 i`ĕb bBKTH2 b2`�Bi mM /Bb+Qm`b 2M 7�p2m` /m MûQHB#û`�HBbK2 [mB b2 HBKBi2 ¨ mM2 +`BiB[m2 /m +QK@KmMBbK2- +QKK2 bǶBH bǶ�;Bbb�Bi /ǶmM2 /BbDQM+iBQM [mB +Qmp`2 iQmi2b H2b TQbbB#BHBiûbX SHmb bm#iBHb bQMi H2b �`;mK2Mi[mB T`ûi2M/2Mi /Ƕāi`2 #�bûb bm` mM2 +QMi`�/B+iBQM K�Bb [mB 2tTHQBi2Mi mM2 �K#B;mśiû Qm QMi mM2 T`ûbmTTQbBiBQM+QMiBM;2Mi2 [mB `2M/2Mi HǶQTTQbBiBQM b2mH2K2Mi +QMi`�B`2X lM 2t2KTH2 /m /2`MB2` +�b 2bi Ŀ bB H2 K2m`i`B2` /2 C2�MMǶ2bi T�b 2M 6`�M+2- BH /QBi āi`2 ¨ HǶûi`�M;2` ŀX

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39 jX _2H�iBQMb HQ;B[m2b 2i BM7û`2M+2b HQ;B[m2b

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lM2 K�MBĕ`2 /2 T`ûb2Mi2` H2b `2H�iBQMb bûK�MiB[m2b T�`KB /2b T?`�b2b 2bi +2 [mǶQM �TT2HH2 mMĿ +�``û /2b QTTQbBiBQMb ŀX G2 THmb �M+B2M /2 +2b +�``ûb- HBû �m MQK /Ƕ�TmHû2 UMû Yf@ 2M Rk8 �pX CX*XV2i /ûp2HQTTû T�` "Qĕ+2 UMû Yf@ 2M 93yV- 2bi #�bû bm` H� i?ûQ`B2 /2b QTTQbBiBQMb /Ƕ�`BbiQi2 U.2HǶBMi2`T`ûi�iBQM- Rd#Rd@keV 2i b2 7�Bi /�Mb H� HQ;B[m2 bvHHQ;BbiB[m2 +QKK2 bmBi ,9y

QKMBb (iQmb) QKMBb MQM U4 MmHHmbV (�m+mM)

MQM QKMBb MQMU4 �HB[mBb 4 MQMMmHHmbV

([m2H[mǶmM)

MQM QKMBb U4 �HB[mBb MQMV(T�b iQmb)

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bm#+QMi`�B`2

bm#�Hi2`M2 bm#�Hi2`M2

+QMi`�/B+iQB`2

+QMi`�/B+iQB`2

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jNX AH 7�mi T`ûbmTTQb2`- TQm` TQmpQB` KQMi`2` [m2 H2b /2mt T?`�b2b M2 T2mp2Mi T�b āi`2 7�mbb2b 2Mb2K#H2b- [mǶBHv �Bi /2b 7āi2bX PM `2pB2M/`� bm` H2 T`Q#HĕK2 /2b i2`K2b pB/2b 2M bvHHQ;BbiB[m2 ¨ H� TX kyeX �`BbiQi2 M2 `2;�`/2T�b H� bm#@+QMi`�`Bûiû +QKK2 mM ivT2 /ǶQTTQbBiBQM- H� +�`�+iû`Bb�Mi +QKK2 mM2 Ŀ Tm`2K2Mi p2`#�H2 ŀ US`2KB2`b�M�HviB[m2b- ej#kRĜjyV Ĝ +2+B T�`+2 [mǶBH MǶ�++2Ti2 T�b H2 T`BM+BT2 /m iB2`b 2t+Hm U+7X TX 8yVX

9yX LQmb `2pB2M/`QMb bm` +2 +�``û /�Mb H2 +QMi2ti2 /2 H� HQ;B[m2 /2b T`û/B+�ib- ¨ H� TX RN9 /�Mb H2 +?�TBi`2 3Xam` HǶ?BbiQB`2 /m +�``û- +7X\ 2i bm` b� `2T`ûb2Mi�iBQM ;ûQKûi`B[m2 +?2x �TTmHû2\X

G2 +�``û /2b QTTQbBiBQMb 38

G� `2H�iBQM /2 bm#�Hi2`M�iBQM 2bi i2HH2 [m2 , mM2 T?`�b2 bm#�Hi2`M2 2bi Mû+2bb�B`2K2Mi p`�B2 bB b�bmT2`�Hi2`M2 2bi p`�B2X *Ƕ2bi H2 +�b /2b `2H�iBQMb /2 ?�mi 2M #�b bm` H2 +�``û /2b QTTQbBiBQMbX9R

*2ii2 `2H�iBQM 2bi +2HH2 /2 H� p�HB/Biû HQ;B[m2 UBH MǶ2bi D�K�Bb H2 +�b [m2- bB HǶ�Miû+û/2Mi 2bi p`�B-�HQ`b H2 +QMbû[m2Mi 2bi 7�mtV- 2i THmb ;ûMû`�H2K2Mi /2 H� +QMbû[m2M+2 bûK�MiB[m2XPM T2mi �/�Ti2` H2 +�``û /2b QTTQbBiBQMb /Ƕ�TmHû2 ¨ H� HQ;B[m2 T`QTQbBiBQMM2HH2 +QKK2 bmBi ,9kX

p ∧ q ¬p ∧ ¬q

p ∨ q p|q- H� #�``2 /2 a?2z2`- /û}MB2 T�` ,

⎜⎜⎜⎜⎜⎝

p q p|qV V FV F VF V VF F V

⎟⎟⎟⎟⎟⎠

+QMi`�B`2

bm#+QMi`�B`2

bm#�Hi2`M2 bm#�Hi2`M2

+QMi`�/B+iQB`2

+QMi`�/B+iQB`2

PM pû`B}2 +2 +�``û /ǶQTTQbBiBQMb ¨ HǶ�B/2 /2b i�#H2b /2 pû`Biû ,*QMi`�`Bûiû AH MǶv � T�b /Ƕ�ii`B#miBQM /2 p�H2m`b /2 pû`Biû [mB `2M/2 Ŀ p ∧ q ŀ 2i Ŀ ¬p ∧ ¬q ŀ

bBKmHi�MûK2Mi p`�BbXam#+QMi`�`Bûiû AH MǶv � T�b /Ƕ�ii`B#miBQM /2 p�H2m`b /2 pû`Biû [mB `2M/2 Ŀ p ∨ q ŀ 2i Ŀ p|q ŀ

bBKmHi�MûK2Mi 7�mtXam#�Hi2`M�iBQM ¨ ;�m+?2 hQmi2 �ii`B#miBQM /2 p�H2m`b /2 pû`Biû [mB `2M/ Ŀ p∧ q ŀ p`�B- `2M/

Ŀ p ∨ q ŀ p`�BXam#�Hi2`M�iBQM ¨ /`QBi2 hQmi2 �ii`B#miBQM /2 p�H2m`b /2 pû`Biû [mB `2M/ Ŀ ¬p ∧ ¬q ŀ p`�B-

`2M/ Ŀ p|q ŀ p`�BX Pɍ +QMp2`b2K2Mi , iQmi2 �ii`B#miBQM [mB `2M/ Ŀ p ∨ q ŀ7�mbb2- `2M/Ŀ p ∧ q ŀ7�mbb2X

*QMi`�/B+iBQM /2b+2M/�Mi2 lM2 �ii`B#miBQM /2 p�H2m`b /2 pû`Biû `2M/ Ŀ p ∧ q ŀ p`�B bB 2ib2mH2K2Mi bB 2HH2 `2M/ Ŀ p|q ŀ 7�mtX

*QMi`�/B+iBQM �b+2M/�Mi2 lM2 �ii`B#miBQM /2 p�H2m`b /2 pû`Biû `2M/ Ŀ p ∨ q ŀ p`�B bbB 2HH2`2M/ Ŀ ¬p ∧ ¬q ŀ 7�mtX

�m HB2m /2 +QKT�`2` /2b i�#H2b /2 pû`Biû- MQmb TQmpQMb +QK#BM2` H2b 7Q`KmH2b /QMi MQmb pQmHQMb/ûi2`KBM2` H2b `2H�iBQMb bûK�MiB[m2b 2M mM2- 2i 2M 7�B`2 mM2 b2mH2 i�#H2 /2 pû`BiûX AH bǶ�;Bi �HQ`b/2 pû`B}2` H2 +�`�+iĕ`2 i�miQHQ;B[m2 /2b 7Q`KmH2b +Q``2bTQM/�Mi2b 2M H�M;�;2 Q#D2i ,ψ 2bi mM2 +QMbû[m2M+2 HQ;B[m2 /2 φ ψ p`�B bB φ 2bi p`�B "φ→ ¬ψ# i�miQHQ;B2φ 2i ψ bQMi HQ;B[m2K2Mi û[mBp�H2Mi2b p`�Bb Qm 7�mt 2Mb2K#H2b "φ↔ ψ# i�miQHQ;B2φ 2i ψ bQMi +QMi`�/B+iQB`2b MB p`�Bb MB 7�mt 2Mb2K#H2b "¬(φ↔ ψ)# i�miQHQ;B2φ 2i ψ bQMi +QMi`�B`2b T�b p`�Bb 2Mb2K#H2b "¬(φ ∧ ψ)# i�miQHQ;B2φ 2i ψ bQMi bm#+QMi`�B`2b T�b 7�mt 2Mb2K#H2b "φ ∨ ψ# i�miQHQ;B2

G2b 2tT`2bbBQMb /�Mb H� +QHQMM2 �m KBHB2m /QBp2Mi āi`2 2Mi2M/m +QKK2 TQ`i�Mi bm` iQmi2b H2bTQbbB#BHBiûb HQ;B[m2- BKTHB+Bi2K2Mi KQ/B}ûb T�` HǶQTû`�i2m` Ŀ BH 2bi p`�B TQm` H2b `�BbQMb Tm`2K2MiHQ;B[m2b [m2 Ę ŀX

9RX § HǶBMp2`b2- QM T�`H2 û;�H2K2Mi /2 `2H�iBQMb bmT2`�Hi2`M2b- i2H [m2 , mM2 T`QTQbBiBQM bmT2`�Hi2`M2 2bi Mû+2b@b�B`2K2Mi 7�mbb2 bB b� bm#�Hi2`M2 2bi 7�mbb2X *Ƕ2bi H2 +�b /2b `2H�iBQMb /2 #�b 2M ?�mi /m i�#H2�m- +Q``2bTQM/�Mi2b�mt +QMp2`b2b /2b BKTHB+�iBQMbX

9kX G� #�``2 /2 a?2z2` 2bi H2 +QMM2+i2m` /û}MB /�Mb H� M2mpBĕK2 +QHQMM2 ¨ H� TX eRX LQmb p2``QMb ¨ H� TX Ne[mǶ2HH2 T2mi b2`pB` TQm` /û}MB` iQmb H2b �mi`2b +QMM2+i2m`b T`QTQbBiBQMM2HbX

Page 11: 2H iBQMbHQ;B[m2b2iBM7û`2M+2b HQ;B[m2bphilipp.philosophie.ch/handouts/logique19-logique3.pdf · TBi`2j _2H iBQMbHQ;B[m2b2iBM7û`2M+2b HQ;B[m2b jXRG2H M; ;2@Q#D2i2iH2Kûi H M; ;2 LQmb

3e jX _2H�iBQMb HQ;B[m2b 2i BM7û`2M+2b HQ;B[m2b

jXe �+?BHH2- H� iQ`im2 2i H� MQ`K�iBpBiû /2 H� HQ;B[m2G� `2H�iBQM 2Mi`2 /2b T?`�b2b [m2 MQmb p2MQMb /2 `2#�TiBb2` T�` H2 MQK #�`#�`2 /2 Ŀ bm#�Hi2`@M�iBQM ŀ 2bi H� `2H�iBQM /2 +QMbû[m2M+2 UHQ;B[m2VX LQmb �pQMb pm [m2 Ŀ q ŀ 2bi mM2 +QMbû[m2M+2HQ;B[m2 /2 Ŀ p ŀ bB 2i b2mH2K2Mi bB Ŀ p→ q ŀ 2bi mM2 i�miQHQ;B2X Ŀ |4 ŀ �TT�`iB2Mi �m Kûi�H�M;�;22i Ŀ → ŀ �TT�`iB2Mi �m H�M;�;2@Q#D2iXGǶBKTQ`i�M+2 /ǶmM2 /BbiBM+iBQM 2Mi`2 H2b /2mt `2H�iBQMb 2bi BHHmbi`û2 T�` mM T�`�/Qt2 [mǶ� bQmH2pûTQm` H� T`2KBĕ`2 7QBb G2rBb *�``QHH- HǶ�mi2m` /2 �HB+2 �m T�vb /2b K2`p2BHH2b- /�Mb mM �`iB+H2 /2/2mt T�;2b U*�``QHH- R3N8VX �+?BHH2- H2 T2`bQMM�;2 /2 HǶ?BbiQB`2- p2mi +QMp�BM+`2 H� iQ`im2 /2 H�pû`Biû /2 Ŀ q ŀX AH T`Q/mBi �HQ`b mM �`;mK2Mi /m ivT2 JQ/mb SQM2Mb U�#`û;û T�` Ŀ JS ŀV- /QMiH� iQ`im2 �++2Ti2 H� pû`Biû /2b T`ûKBbb2b ,

UjXkjVp

p→ qq

G� iQ`im2- +2T2M/�Mi- `ûTHB[m2 [m2 +2i �`;mK2Mi 2bi mM 2Mi?vKĕK2- [mǶBH v K�M[m2 mM2 T`ûKBbb2-¨ b�pQB` [m2 Ŀ q ŀ bǶ2MbmBi /2 Ŀ p ŀ 2i /2 Ŀ p→ q ŀX 1M `ûTQMb2- �+?BHH2 2bi /Ƕ�++Q`/ /Ƕ�DQmi2`+2ii2 �{`K�iBQM +QKK2 T`ûKBbb2 bmTTHûK2Mi�B`2 ¨ UjXkjV [mB /2pB2Mi �HQ`b ,

UjXkj′Vp

p→ q(p ∧ (p→ q))→ q

q

J�Bb H� iQ`im2 MǶ2bi iQmDQm`b T�b +QMp�BM+m2 [m2 qX 1HH2 2bi /Ƕ�++Q`/ [mǶBH bǶ2MbmBi /2b i`QBbT`ûKBbb2b Ĝ Ŀ (p∧ (p→ q))→ q ŀ- Ŀ p→ q ŀ 2i Ŀ p ŀĜ [m2 q- K�Bb 2HH2 BMbBbi2 TQm` [mǶQM `�DQmi2+2 7�Bi@+B +QKK2 T`ûKBbb2 ¨ UjXkj′VX �+?BHH2 H� HmB �++Q`/2 2i b2 i`Qmp2 /QM+ /�Mb +2 [mǶQM �TT2HH2mM2 Ŀ `û;`2bbBQM ¨ HǶBM}MB ŀ c BH MǶ�``Bp2`� D�K�Bb ¨ +QMp�BM+`2 H� iQ`im2 [m2 q ,

UjXkj′′V pp→ q

q

pp→ q

(p ∧ p→ q)→ qq

pp→ q

(p ∧ (p→ q))→ q(p ∧ (p→ q) ∧ ((p ∧ (p→ q))→ q))→ q

q . . .

G� iQ`im2 � Tm `B/B+mHBb2` �+?BHH2 ;`�+2 ¨ HǶ�#b2M+2 /2 /BbiBM+iBQM 2Mi`2 H� `2H�iBQM /2 +QMbû[m2M+2HQ;B[m2- [mB DmbiB}2 H� p�HB/Biû /m b+?ûK� /ǶBM7û`2M+2 [mǶQM �TT2HH2 Ŀ KQ/mb TQM2Mb ŀ- 2i H�`2H�iBQM /ǶBKTHB+�iBQM K�iû`B2HH2X9j

G� T`Q#HûK�iB[m2 T2mi āi`2 KBb2 2M 7Q`K2 bmBp�Mi2 ,Ç _B2M /Ƕ�mi`2 MǶ2bi Mû+2bb�B`2 TQm` Hû;BiBK2` H� T`Q;`2bbBQM- /�Mb mM �`;mK2Mi p�HB/2- /2b

T`ûKBbb2b ¨ H� +QM+HmbBQM- [m2 H� `2+QMM�Bbb�M+2 /2 +2ii2 p�HB/Biû- +Ƕ2bi@¨@/B`2 /m +�`�+iĕ`2i�miQHQ;B[m2 /2 HǶBKTHB+�iBQM +Q``2bTQM/�Mi2X

Ç _�DQmi�Mi +2ii2 BKTHB+�iBQM +QKK2 T`ûKBbb2 T`Q/mBi mM �mi`2 �`;mK2Mi- /QMi H� p�HB/BiûT`ûbmTTQb2 H2 +�`�+iĕ`2 i�miQHQ;B[m2 /ǶmM2 �mi`2 BKTHB+�iBQM +Q``2bTQM/�Mi2X

AH 2bi TQbbB#H2 /2 iQm`M2` HǶ�`;mK2Mi 2M [m2biBQM Qmp2`i2 +QM+2`M�Mi H� 7Q`+2 MQ`K�iBp2 /2b�`;mK2Mib HQ;B[m2K2Mi p�HB/2b , Ŀ [mǶ2bi@+2 [m2 MQmb 2Mi2M/QMb T�` H� ǵMû+2bbBiû HQ;B[m2Ƕ /ǶmM�`;mK2Mi p�HB/2 bB 2HH2 2bi BKTmBbb�Mi2 ¨ 7Q`+2` H� iQ`im2 iāim2 /Ƕ�++2Ti2` b� +QM+HmbBQM \ ŀX

9jX _vH2 URN8y- k93V �TT2HH2 HǶBKTHB+�iBQM +Q``2bTQM/�Mi2 H2 Ŀ T`BM+BT2 ŀ /2 HǶBM7û`2M+2 /QMi H�[m2HH2 2HH2 2biĿ �TTHB[mû2 ŀ , Ŀ EMQrBM; ǵB7 p- i?2M qǶ Bb- i?2M- `�i?2` HBF2 #2BM; BM TQbb2bbBQM Q7 � `�BHr�v iB+F2iX Ai Bb ?�pBM;� HB+2M+2 Q` r�``�Mi iQ K�F2 � DQm`M2v 7`QK GQM/QM iQ Pt7Q`/X UEMQrBM; � p�`B�#H2 ?vTQi?2iB+�H Q` ǵH�rǶ Bb HBF2?�pBM; � b2�bQM iB+F2iXV �b � T2`bQM +�M ?�p2 � iB+F2i rBi?Qmi �+im�HHv i`�p2HHBM; rBi? Bi �M/ rBi?Qmi 2p2` #2BM;BM GQM/QM Q` ;2iiBM; iQ Pt7Q`/- bQ � T2`bQM +�M ?�p2 �M BM72`2M+2 r�``�Mi rBi?Qmi �+im�HHv K�FBM; �Mv BM72`2M+2b�M/ 2p2M rBi?Qmi 2p2` �+[mB`BM; i?2 T`2KBbb2b 7`QK r?B+? iQ K�F2 i?2KX ŀ URN8y- k8yVX h`�/m+iBQM , Ŀ a�pQB` Ŀ bBp �HQ`b q ŀ 2bi [m2H[m2 +?Qb2 +QKK2 āi`2 2M TQbb2bbBQM /ǶmM #BHH2i /2 i`�BMX *Ƕ2bi �pQB` mM2 HB+2M+2 Qm H2 TQmpQB`/2 7�B`2 H2 pQv�;2 /2 GQM/`2b ¨ Pt7Q`/X Ua�pQB` mM T`BM+BT2 Qm HQB ;ûMû`�H 2bi +QKK2 �pQB` mM �#QMM2K2MiXV AH 2biTQbbB#H2 [mǶmM2 T2`bQMM2 �Bi mM iB+F2i b�Mb HǶmiBHBb2` TQm` mM pQv�;2- b�Mb āi`2 D�K�Bb ¨ GQM/`2b 2i b�Mb D�K�Bb�``Bp2` ¨ Pt7Q`/- 2i �BMbB mM2 T2`bQMM2 T2mi �pQB` H2 /`QBi ¨ mM2 BM7û`2M+2 b�Mb D�K�Bb 2M 7�B`2 2i b�Mb D�K�Bb�+[mû`B` H2b T`ûKBbb2b ¨ T�`iB` /2b[m2HH2b 2HH2 TQm``�Bi H� 7�B`2X ŀ

�+?BHH2- H� iQ`im2 2i H� MQ`K�iBpBiû /2 H� HQ;B[m2 3d

"B2M [m2 H� M�im`2 2t�+i2 /2 H� ǵ7�mi2Ƕ /2 H� iQ`im2 2bi +?�m/2K2Mi +QMi2biû2- MQmb TQmpQMb�m KQBMb /B`2 [mǶBH bǶ�;Bi- 2M T�`iB2 �m KQBMb- /m 7�Bi [mǶ2HH2 T`2M/ HǶBKTHB+�iBQM 7Q`K2HH2 U[mB`2M/ HǶBM7û`2M+2 p�HB/2V TQm` mM2 BKTHB+�iBQM K�iû`B2HH2 U[m2 HǶQM /QBi `�DQmi2` +QKK2 T`ûKBbb2bmTTHûK2Mi�B`2V 2i +QM7QM/ �HQ`b H�M;�;2 Q#D2i 2i Kûi�H�M;�;2X *2 Mƾm/ /2 `ûTQMb2 T2mi āi`2bmTTH2K2Miû /2 /Bzû`2Mi2b K�MBĕ`2b , MQmb TQmpQMb- T�` 2t2KTH2- `ûTQM/`2 ¨ H� iQ`im2

Ç [mǶBH M2 bǶ�;Bi T�b /ǶmM2 T`ûKBbb2 bmTTHûK2Mi�B`2- K�Bb THmiƬi /ǶmM2 +QM/BiBQM /2 +�/`2 c99

Ç [m2 H� `ĕ;H2 /ǶBM7û`2M+2 2bi +QMbiBimiBp2 /2 H� T`�iB[m2 [mǶ2HH2 ;Qmp2`M2- /2 bQ`i2 [m2 bQM�++2Ti�iBQM +QKK2 T`ûKBbb2 2bi BM�TT`QT`Bû2 c

Ç [m2 H� KQ/�HBiû 2M [m2biBQM MǶ2bi T�b HǶQ#HB;�iBQM- K�Bb H� T2`KBbbBQM , H� p�HB/Biû /ǶmM2BM7û`2M+2 HQ;B[m2 MQmb T2`K2i /2 #�b2` MQi`2 +`Qv�M+2 2M b� +QM+HmbBQM bm` MQi`2 �++2Ti�iBQM/2 b2b T`ûKBbb2b c98

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J�Bb BH MǶ�p�B2Mi �m+mM2 DmbiB}+�iBQM /2 +`QB`2

Page 12: 2H iBQMbHQ;B[m2b2iBM7û`2M+2b HQ;B[m2bphilipp.philosophie.ch/handouts/logique19-logique3.pdf · TBi`2j _2H iBQMbHQ;B[m2b2iBM7û`2M+2b HQ;B[m2b jXRG2H M; ;2@Q#D2i2iH2Kûi H M; ;2 LQmb

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S�` H2 KāK2 `�BbQMM2K2Mi [mǶ�mT�`�p�Mi- MQmb 2M /û/mBbQMb H� +QM+HmbBQM [m2 bQBi MQmb /2p`BQMb#HQ[m2` A bQBi MQmb /2p`BQMb #HQ[m2` B Ur ∨ sVXlM2 [m2biBQM /B{+BH2 2i T`Q7QM/2 bQmH2pû2 T�` +2b /Bb+mbbBQMb 2bi +2HH2 /2 H� `2H�iBQM 2Mi`2 HǶBKTHB@+�iBQM K�iû`B2HH2 U2i THmb ;ûMû`�H2K2Mi H2b +QM/BiBQMM2HH2b 2M H�M;m2 M�im`2HH2V 2i H� T`Q#�#BHBiû+QM/BiBQMM2HH2X8y a�m7 /�Mb /2b +�b i`ĕb T�`iB+mHB2`b- BH MǶ2bi T�b TQbbB#H2 /2 /û}MB` mM +QMM2+i2m`+QM/BiBQMM2H /QMi H� T`Q#�#BHBiû 2bi H� KāK2 [m2 H� T`Q#�#BHBiû +QM/BiBQMM2HH2 +Q``2bTQM/�Mi2X1M /Ƕ�mi`2b KQib- MQmb M2 TQmpQMb T�b 2tTHB[m2` H� T`Q#�#BHBiû +QM/BiBQMM2HH2 2M i2`K2b /2 H�T`Q#�#BHBiû /ǶmM +QM/BiBQMM2HXG� T`Q#�#BHBiû +QM/BiBQMM2HH2 /ǶmM ûpĕM2K2Mi 2bi b� T`Q#�#BHBiû bQmb [m2H[m2b ?vTQi?ĕb2b �mtB@HB�B`2b- b� T`Q#�#BHBiû ûi�Mi /QMMû [m2 +2`i�BMb �mi`2b ûpĕM2K2Mib b2 T`Q/mBb2MiX 1HH2 2bi /ǶmM2BKTQ`i�M+2 7QM/�K2Mi�H2- ¨ H� 7QBb 2M Kûi�T?vbB[m2 Upm [mǶ�m+mM ûHûK2Mi b�m7 T2mi@āi`2 H2 "B;"�M; MǶ� T�b /2 T`û/û+2bb2m`bV 2i 2M ûTBbiûKQHQ;B2 T`Q#�#BHBbi2 Upm [mǶ�m+mM2 ?vTQi?ĕb2 T2miāi`2 ûp�Hmû2 b�m7 2M T`2M�Mi TQm` �+[mBb /Ƕ�mi`2b TBĕ+2b /ǶBM7Q`K�iBQMVX .�Mb +2ii2 /2`MBĕ`2 miB@HBb�iBQM- 2HH2 MQmb T2`K2i /2b T`û/B+iBQMbX amTTQbQMb- T�` 2t2KTH2- [m2 H� T`Q#�#BHBiû Ł Mm2 ł[mǶmM2 T2`bQMM2 /QMMû iQmbb2 2bi /2 5W UMQmb miBHBbQMb HǶQTû`�i2m` P TQm` 2tT`BK2` +2 7�Bi ,S(p) = 0.05VX úi�Mi /QMMû- +2T2M/�Mi- [m2 +2ii2 T2`bQM �Bi H� ;`BTT2 UqV- H� T`Q#�#BHBiû [mǶ2HH2iQmbb2 �m;K2Mi2 ¨ 75W- +2 [m2 MQmb 2tT`BKQMb +QKK2 T`Q#�#BHBiû +QM/BiBQMM2HH2 +QKK2 bmBi ,S(p|q) = 0.75X AH 2tBbi2 mM2 /Bb+mbbBQM pBp2 bm` H� [m2biBQM /2 b�pQB` bǶBH 7�mi T`2M/`2 H� T`Q#�#BHBiû+QM/BiBQMM2HH2 +QKK2 T`BKBiBp2 UH� T`Q#�#BHBiû Mm2 b2`� �HQ`b H� +QM/BiBQM�HBb�iBQM bm` mM2 i�miQ@HQ;B2V Qm H� /û}MB` +QKK2 BH 2bi 7�Bi /�Mb H2b i?ûQ`B2 �tBQK�iB[m2 /2 T`Q#�#BHBiû /2 EQHKQ;Q`Qp ,

UjXk8V S(p|q) := S(p∧q)S(q)

.�Mb HǶBMi2`T`ûi�iBQM #�vûbB2MM2 /2 H� T`Q#�#BHBiû- H� T`Q#�#BHBiû +QM/BiBQMM2HH2 S(p|q) 2tT`BK2HǶBM+Q`TQ`�iBQM /ǶmM2 MQmp2HH2 BM7Q`K�iBQM U[m2 qV 2M pm2 /2 H� T`Q#�#BHBiû [m2 p , �v�Mi �TT`Bb[m2 q- MQmb /2p`BQMb i2MB` +QKTi2 /2 +2ii2 MQmp2HH2 BM7Q`K�iBQM /�Mb MQi`2 2biBK�iBQM /2 H�T`Q#�#BHBiû /2 p 2i �HQ`b HmB �ii`B#m2` H� T`Q#�#BHBiû +QM/BiBQMM2HH2XSQm` H2b T`Q#�#BHBiûb +QM/BiBQMM2HH2b- BH 2bi bQmp2Mi i`ĕb BKTQ`i�Mi /2 /BbiBM;m2` H� +QM/BiBQM /m+QM/BiBQMMû , 2M ;ûMû`�H S(p|q)- MǶ2bi T�b /m iQmi H� KāK2 +?Qb2 [m2 S(q|p)X amTTQbQMb [m2 MQmb�pQMb mM i2bi }�#H2 TQm` H� /2M;m2 , S(T2`bQMM2 A � ûiû i2biû2 TQbBiB7 TQm` H� /2M;m2 | T2`bQMM2A � H� /2M;m2) = 0.97X G� }�#BHBiû /ǶmM i2H i2bi bB;MB}2 [mǶBH v �m`� T2m /2 Ł 7�mt Mû;�iB7b ł , mM`ûbmHi�i TQbBiB7 2bi }�#H2 T�`+2 [mǶBH 2bi i`ĕb `�`2 U[m2 /�Mb 3W /2b +�bV [mǶmM2 T2`bQMM2 �v�Mi H�/2M;m2 M2 bQBi T�b /B�;MQbiB[mû TQbBiBp2K2Mi �m i2bi /2 H� /2M;m2X �mi`2K2Mi /Bi- BH MǶv � [m2T2m /ǶBM72+iûb [mB T�bb2Mi BM�T2`Ïmb �m i2biX GǶ2tBbi2M+2 /ǶmM i2H i2bi 2bi i`ĕb #B2M +QKT�iB#H2�p2+ mM MQK#`2 �bb2x ûH2pû /2 Ł 7�mt TQbBiB7b ł , 2M 2z2i- BH 2bi bQmp2Mi `�BbQMM�#H2 /ǶmiBHBb2` mMi2bi Ł bm`@b2MbBiB7 ł- [mB T`Q/mBi /2b `ûbmHi�ib TQbBiB7b �mbbB /�Mb [m2H[m2b +�b Qɍ H� T2`bQMM2 2bi 2M2z2+i b�BM2X LQmb TQmpQMb �HQ`b �pQB` S( T2`bQMM2 A � H� /2M;m2 | T2`bQMM2 A � ûiû i2biû TQbBiB7TQm` H� /2M;m2) = 0.5- +Ƕ2bi@¨@/B`2 �pQB` mM2 bBim�iBQM Qm mM `ûbmHi�i TQbBiB7 /ǶmM T`2KB2` i2biM2 MQmb BM/B[m2 [mǶmM2 T`Q#�#BHBiû /2 50W [m2 H� T2`bQMM2 2M [m2biBQM �Bi `û2HH2K2Mi �ii`�TûH� /2M;m2 Ĝ /Ƕ�mi`2b i2bib- THmb +QKTHB[mûb- b2`QMi �HQ`b Mû+2bb�B`2bX �mi`2K2Mi /Bi- H2 i2bi +`û2

8yX G2 HBp`2 /2 �/�Kb Ŀ h?2 GQ;B+ Q7 *QM/BiBQM�HbX �M �TTHB+�iBQM Q7 S`Q#�#BHBiv iQ .2/m+iBp2 GQ;B+ ŀ URNd8V2i HǶ�`iB+H2 /2 .�pB/ G2rBb Ŀ S`Q#�#BHBiB2b Q7 *QM/BiBQM�Hb �M/ *QM/BiBQM�H S`Q#�#BHBiB2b ŀ URNdeV QMi BMBiBûb 2i7Q`i2K2Mi BM~m2M+ûb +2 /û#�iX

Page 13: 2H iBQMbHQ;B[m2b2iBM7û`2M+2b HQ;B[m2bphilipp.philosophie.ch/handouts/logique19-logique3.pdf · TBi`2j _2H iBQMbHQ;B[m2b2iBM7û`2M+2b HQ;B[m2b jXRG2H M; ;2@Q#D2i2iH2Kûi H M; ;2 LQmb

Ny jX _2H�iBQMb HQ;B[m2b 2i BM7û`2M+2b HQ;B[m2b

/2 7�mbb2b �H�`K2b- K�Bb �m pm /2 H� T`Q#�#BHBiû S(p|q)- H� 7�B#H2 T`Q#�#BHBiû S(q|p) 2bi KQBMbBM/ûbB`�#H2 , MQmb T`û7û`QMb �pQB` THmb /Ƕ�H�`K2b +Qmp`�Mi Nd W /2b +�b /ǶBM72+iBQMb- THmiƬi [m2/Ƕ�pQB` KQBMb /Ƕ�H�`K2b 2i [m2 THmb /2 T2`bQMM2b BM72+iû2b T�bb2Mi BM�T2`Ïm2bX8R

AH 2tBbi2- +2T2M/�Mi- mM2 `2H�iBQM K�i?ûK�iB[m2 i`ĕb BKTQ`i�Mi2 2Mi`2 H2b /2mt ivT2b /2 T`Q#�@#BHBiûb +QM/BiBQMM2HH2b- �TT2Hû2 H2 Ŀ i?ûQ`ĕK2 /2 "�v2b ŀ ,

UjXkeV S(p|q) := S(p)·S(q|p)S(q))

*2 7�K2mt i?ûQ`ĕK2 /Bi [m2 H� T`QTQ`iBQM 2Mi`2 H2b T`Q#�#BHBiûb +QM/BiBQMM2HH2 S(p|q) 2i S(q|p)2bi H� KāK2 [m2 H� T`QTQ`iBQM 2Mi`2 S(p) 2i S(q)X.�Mb #2�m+QmT /2 +�b- MQmb M2 TQmpQMb T�b /ûi2`KBM2` /B`2+i2K2Mi H� T`Q#�#BHBiû BM+QM/BiBQM@M2HH2 /2 H� +QM/BiBQM S(q) Ĝ /�Mb H2 +�b Qɍ BH bǶ�;Bi /ǶmM `ûbmHi�i /2 i2bi TQbBiB7- T�` 2t2KTH2- 2HH2/2p`�Bi āi`2 +�H+mHû2 bm` iQmi2 H� TQTmH�iBQM- i2biû2 Qm MQMX S�`+2 [m2 +2ii2 T`Q#�#BHBiû S(q) 2biH� bQKK2 /2 H� T`Q#�#BHBiû /2 Ŀ q ŀ /�Mb H2 +�b [m2 p 2i H� T`Q#�#BHBiû /2 Ŀ q ŀ /�Mb H2 +�b [m2¬p , S(q) = S(q ∧ p) + S(q ∧ ¬p) 2i T�`+2 [m2 +2b /2mt /2`MB2`b bQMi û;�H2b ¨ S(p) · S(q|p) 2i ¨S(¬p) · S(q|¬p) `2bT2+iBp2K2Mi- ;`�+2 ¨ H� /û}MBiBQM /2 H� T`Q#�#BHBiû +QM/BiBQMM2HH2- MQmb �pQMb

UjXkdV S(p|q) := S(p)·S(q|p)S(p)·S(q|p)+ S(¬p)·S(q|¬p)

.�Mb MQi`2 2t2KTH2- +2ii2 7Q`KmH2 MQmb T2`K2i /2 +�H+mH2` H� T`Q#�#BHBiû [m2 [m2H[mǶmM i2biûTQbBiBp2K2Mi 2bi `û2HH2K2Mi K�H�/2 US(/2M;m2 | TQbBiB7)V bm` H� #�b2 /2 H� T`Q#�#BHBiû /2 H� K�H�/B2/�Mb H� TQTmH�iBQM i2biû2 US(d) = 1WV ,

S(d|+) =S(d) · S(+|d)

S(d) · S(+|d) + S(¬d) · S(+|¬d)

=0.1 · · · 0.97

0.1 · 0.97 + 0.9 · 0.03 =0.097

0.097 + 0.027=

0.097

0.124= 0.78226

lM2 T2`bQMM2 i2biû2 TQbBiBp2K2Mi �m`� /QM+ mM2 T`Q#�#BHBiû /2 THmb /2 78W /2 `û2HH2K2Mi āi`2K�H�/2X

jXd G� +QMbû[m2M+2 HQ;B[m2LQmb TQmpQMb K�BMi2M�Mi MQi2` THmbB2m`b T`QT`Bûiûb /2 H� `2H�iBQM /2 +QMbû[m2M+2 HQ;B[m2 [mǶQM� �TT2Hû2 Ŀ |4 ŀX8k

S`2KBĕ`2K2Mi- `2K�`[mQMb [mǶmM2 �bb2`iBQM /2 +QMbû[m2M+2 HQ;B[m2 Ŀ φ |4 ψ ŀ`2pB2Mi ¨ /B`2 [m2iQmi2 �ii`B#miBQM /2 p�H2m`b /2 pû`Biû [mB `2M/ φ p`�B `2M/ û;�H2K2Mi ψ p`�BX �BMbB- H� +QMbû[m2M+2HQ;B[m2 2bi �z�B`2 /2 p�HB/Biû- TmBb[m2 b2HQM iQmi2 TQbbB#BHBiû HQ;B[m2- bB φ 2bi p`�B- �HQ`b ψ 2bi p`�Bû;�H2K2MiX *2ii2 T`QT`Bûiû M2 H� /BbiBM;m2 +2T2M/�Mi T�b /2 HǶBKTHB+�iBQM K�iû`B2HH2- 2i BH MQmb

8RX LQmb /2pQMb āi`2 T`m/2Mib /2 M2 T�b bm`@;ûMû`�HBb2` +2 /B�;MQbiB[m2X .�Mb MQi`2 i`�/BiBQM Hû;�H2- T�` 2t2KTH2-H� bBim�iBQM 2bi 2t�+i2K2Mi HǶBMp2`b2 , BH 2bi #2�m+QmT TB`2 /2 TmMB` /2b BMMQ+2Mib U7�mt TQbBiB7V [m2 /2 M2 T�bTmMB` H2b +QmT�#H2b U7�mt Mû;�iB7VXHH � KāK2 ûiû �`;mK2Miû [m2 H� 7�mi2 /2 T`BpBHû;B2` H2b 7�mt Mû;�iB7b bm` H2b 7�mt TQbBiB7b UH� 7�mi2 /2 M2T�b +QKT`2M/`2 [m2 +Ƕ2bi TB`2 /2 /B`2 [m2H[m2 +?Qb2 /2 7�mt U7�mt TQbBiB7V [m2 /2 M2 T�b /B`2 [m2H[m2 +?Qb2/2 p`�B- 7�mt Mû;�iB7V 2bi H2 T`Q#HĕK2 Kûi?Q/QHQ;B[m2 7QM/�K2Mi�H2 /2 H� b+B2M+2 2tTû`BK2Mi�H2 +QMi2KTQ@`�BM2X *7X H2b �`iB+H2b /�Mb H2 1+QMQKBbi 2M Q+iQ#`2 kyRj U?iiTb,ffrrrX2+QMQKBbiX+QKfH2�/2`bfkyRjfRyfkRf?Qr@b+B2M+2@;Q2b@r`QM; 2i ?iiTb,ffrrrX2+QMQKBbiX+QKf#`B27BM;fkyRjfRyfR3fi`Qm#H2@�i@i?2@H�#V 2i H2 #HQ;?iiTb,ff`2THB+�iBQMBM/2tX+QKX

8kX SQm` 7�+BHBi2` HǶ2tTQbBiBQM- MQmb M2 +QMbB/û`QMb B+B [m2 /2b �`;mK2Mib [mB MǶQMi [mǶmM MQK#`2 }MB /2 T`ûKBbb2bXJ�Bb H2b T`QT`Bûiûb /2 H� p�HB/Biû 2M [m2biBQM p�H2Mi �mbbB TQm` /2b �`;mK2Mib [mB 2M QMi mM MQK#`2 BM}MBX LQmb`2pB2M/`QMb ¨ +2b T`QT`Bûiûb /2 `2H�iBQMb ¨ H� TX jkk �m +?X R8X

G� +QMbû[m2M+2 HQ;B[m2 NR

7�mi /QM+ +QMiBMm2` MQi`2 BMp2biB;�iBQM TQm` HǶ2M /Bzû`2M+B2`X SQm` +2H�- BH MQmb 7�mi T`2M/`22M bû`B2mt H2 7�Bi [m2 Ŀ |4 ŀ/ûMQi2 mM2 `2H�iBQM [mB `2HB2 /2b T?`�b2b- #B2M [m2 Ŀ → ŀ2bi mM+QMM2+i2m`- [mB MQmb b2`b TQm` 7�B`2 /2 T?`�b2b THmb bBKTH2b /2b �mi`2b T?`�b2b- THmb +QKTH2t2bX1M ;ûMû`�H- H2b �`;mK2Mib T2mp2Mi �pQB` THmbB2m`b T`ûKBbb2b- K�Bb MǶQMi [mǶmM2 b2mH2 +QM+HmbBQMX8j

*QKK2 BH 2bi +QmiȿK2 2M K�i?ûK�iB[m2b- MQmb i2MQMb +QKTi2 /2 +2ii2 KmHiBTHB+Biû 2M +QMbB/û`�MiH2b T`ûKBbb2b +QKK2 mM 2Mb2K#H2 2i H� +QMbû[m2M+2 HQ;B[m2 +QKK2 mM `2H�iBQM 2Mi`2 mM 2Mb2K#H2/2 T`ûKBbb2b 2i mM2 +QM+HmbBQMX1M ;ûMû`�H- H2b `2H�iBQMb T2mp2Mi TQbbû/2` /Bzû`2Mib ivT2b /2 T`QT`BûiûbX S�` `�TTQ`i ¨ H� `2H�iBQM/2 +QMbû[m2M+2 HQ;B[m2- Ŀ |4 ŀ- MQmb `2K�`[mQMb- iQmi /Ƕ�#Q`/- [m2 HǶQ`/`2 /2b T`ûKBbb2b MǶ2biT�b T2`iBM2Mi TQm` ûp�Hm2` mM �`;mK2Mi +QKK2 p�HB/2 Qm MQM p�HB/2X *2b T`ûKBbb2b bQMi /QM+T2`Kmi�#H2b ,

UT2`KV {p1, p2, . . . pn} |4 r 4⇒ {p2, p3, p1, . . . pn, . . . p7, . . . } |4 r

*2 MǶ2bi T�b 2M +?�M;2�Mi HǶQ`/`2 /2b T`ûKBbb2b [m2 HǶQM T2mi `2M/`2 MQM p�HB/2 mM �`;mK2Mip�HB/2X *2ii2 T`QT`Bûiû /2 T2`Kmi�#BHBiû /2 H� `2H�iBQM /2 +QMbû[m2M+2 HQ;B[m2 MQmb �TT`2M/ [m2H2b TQmpQB`b BM7û`2MiB2Hb /ǶmM2 KmHiBim/2 /2 T`ûKBbb2b `2bi2Mi BM+?�M;û bQmb /2b T2`Kmi�iBQMb /2+2ii2 KmHiBim/2X89

1M b2+QM/ HB2m- H� +QMbû[m2M+2 HQ;B[m2 2bi mM2 `2H�iBQM KQMQiQM2 ,

UKQMV {p1, p2, . . . pn} |4 r 4⇒ {p1, p2, . . . pn, q1, q2, . . . qm} |4 r

aB pQmb i2M2x mM �`;mK2Mi p�HB/2- pQi`2 BMi2`HQ+mi2m` M2 T2mi T�b pQmb +QMi`2/B`2 2M HmB �DQm@i�Mi mM2 T`ûKBbb2 bmTTHûK2Mi�B`2X �mi`2K2Mi /Bi- �DQmi2` /2b T`ûKBbb2b {q1, q2, . . . qm} /�MbHǶ2t2KTH2 +B@/2bbmb M2 T2mi T�b BMp�HB/2` H� +QMbû[m2M+2 bûK�MiB[m2 Q#i2Mm2 �p2+ H2b T`ûKBbb2b{p1, p2, . . . pn}X lM i2H �DQmi 2bi �TT2Hû Ŀ �z�B#HBbb2K2Mi ŀ /2 HǶBM7û`2M+2 [mB TQm`i�Mi `2bi2 p�HB/2XU.�Mb H2 +�b Qɍ HǶQM �DQmi2 mM2 T`ûKBbb2 [mB +QMi`2/Bi mM2 T`ûKBbb2 /ûD¨ T`ûb2Mi2- Ŀ r ŀ bǶ2MbmBiT�`+2 [m2 MǶBKTQ`i2 [m2HH2 T?`�b2 2bi mM2 +QMbû[m2M+2 HQ;B[m2 /ǶmM2 +QMi`�/B+iBQM- +Ƕ2bi@¨@/B`2T�` H2 b+?ûK� /ǶBM7û`2M+2 �TT2Hû Ŀ 2t 7�HbQ [mQ/HB#2i ŀXV88 *2ii2 T`QT`Bûiû bǶ�TT2HH2 Ŀ KQMQiQ@MB2 ŀ T�`+2 [mǶ2HH2 bB;MB}2 [m2 H� 7QM+iBQM [mB T`2M/ +QKK2 �`;mK2Mi mM +2`i�BM 2Mb2K#H2 /2T`ûKBbb2b 2i /QMM2 +QKK2 p�H2m` H2m`b +QMbû[m2M+2b 2bi KQMQiQM2 /�Mb H2 b2Mb K�i?ûK�iB[m2/2 +2 i2`K2 , `2T`ûb2Miû +QKK2 +Qm`#2- H� HB;M2 M2 #�Bbb2`� T�bXG� p�HB/Biû 2bi i`�MbBiBp2 ,

Ui`�MbV {p1, . . . pn} |4 r � {r, q1, . . . qn} |4 s 4⇒ {p1, . . . pn, q1, . . . qm} |4 s

aB Ŀ r ŀ bǶ2MbmBi /2b T`ûKBbb2b Ŀ p1 ŀ- Ŀ p2 ŀ- 2i+X 2i bB Ŀ s ŀ bǶ2MbmBi /2 +2ii2 T`ûKBbb2 BMi2`Kû/B�B`2Ŀ r ŀ 2i /2b T`ûKBbb2b Ŀ q1 ŀ- Ŀ q2 ŀ- 2i+X- �HQ`b QM T2mi /B`2+i2K2Mi BM7û`2` Ŀ s ŀ Ub�Mb �pQB`#2bQBM /ǶBM7û`2` /Ƕ�#Q`/ Ŀ r ŀ /2 Ŀ p1 ŀ- Ŀ p2 ŀ 2i+XVX8e

8jX *2+B MǶ2bi T�b p`�B /2 iQmi2b H2b HQ;B[m2b- +QKK2 BH 2tBbi2Mi /2b HQ;B[m2b ¨ +QM+HmbBQMb KmHiBTH2bX

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88X G� `ĕ;H2 /ǶBM7û`2M+2 Ŀ 2t 7�HbQ [mQ/HB#2i ŀ +Q``2bTQM/ ¨ H� i�miQHQ;B2 Ŀ p→ (¬p→ q) ŀ /QMi MQmb T�`H2`QMb¨ H� TX Rk9X

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