JAIST 北陸先端科学技術大学院大学t-nemoto/summerschool.pdf2M8% TD. Troelstra and van...
Transcript of JAIST 北陸先端科学技術大学院大学t-nemoto/summerschool.pdf2M8% TD. Troelstra and van...
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=.*tX~g
,5?BR (L&h
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0. \!
1. =.*tXHO)
2. Z@H BHKra
3. s=.6}
4. BtH"3Xt
5. fVMNj}
6. CantorN&Lt,j}HWeak Koenig’s Lemma
7. Heine-BorelNo$j}H Brouwer’s Fan Theorem
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=.*tXHO)
• -B*tX (Kronecker, Hilbert)• DR*tX (Poincaré, Weyl, etc..)• >QgAtX (Brouwer, etc..)• F"*tX (Markov, etc..)• Bishop.=.*tX (Bishop, etc..)
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=.*tXHO) 1. -B*tX
-B*tX (Kronecker, Hilbert, etc..)
V+3tO@NnC?bN@,,>OMVNnC?bNG"kW
(Kronecker, 1886)
• qN*K (-B*K)=;k=$@1,tX*P]G"k.
=&7?=$eNi;bBz*JbNG"k.
• 8gd=NeNi;JINj]*J50O,-B*tXNP]GOJ$.
• 3N)lGtXN57b-r(=&H7?N,HilbertNWm0i` (1900/")
• Kronecker O8_Z@OqN*Kror~?9P]r-B9FCWG?(J1lPZ@7?3HK
JiJ$H7,Sf' “A ∨ ¬A”K]j*J+rr(7F$?.
• HilbertOSf'r'aF$?.
Kronecker
Hilbert
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=.*tXHO) 2. DR*tX
DR*tX (Poincaré, Weyl, etc..)
dj 2 AH B ⊆ AKP7F B r^`G.N ANt,2,8_9k3Hr(7J5$.
sz: B = {C : C O ANt,2G, B ⊆ C}KP7D =
⋂
B H9k.(]$sH) D rjA9kNKHC? B KP7F
D ∈ B G"k.
• sDR*jAHO, eNh&JV?+rjA9kNK=l+H,09k/i9r2H9kjAWN
3H.
• DR*tXOp\*KOsDR*jAr'aJ$,,+3te@1O'ak3H,?$.
• Sf'OlLK'aF$k.
Poincaré
Weyl
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=.*tXHO) 3. >QgAtX
>QgAtX
• [TD]Khkp\}0N^Ha• tXHO:@*:*r7&bNG"j, -fsN`nNfK"kbNGOJ$.
tX*@lO>THNdjhjN?aKQ$k
jJG"j\AGOJ$.
• tX*?jN?6Of9NN1KM89k.?j A,?G"kHO ANZ@,?(ilk3HG,6G"kHO A+i7br31k3HNZ@,?(ilk3HG"k.
• tXHO free creationG"k. c(P,f9,W$D-G 1`:DjA9k5Bsb,tX*
P]HJj&k.
Brouwer
• Sf'OlLK'aJ$.• BrouwerH HilbertOP)7F$?.• “BteNXtO9YF"3G"k”JIr3/C'*Jx}r}D.• >QgA@}O,>QgAtXN@}Nt,r Heytingi,0}7FNO=7?bN.
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=.*tXHO) 4. F"*tX
F"*tX
• tX*P]HO"k4j:`G"k. ?@7,~V&uV*)sOJ$bNH9k.
• 8_Z@OqN*Kror~?9P]r=.9k"k4j:`r?(J1lPJiJ$.
• A ∨ B NZ@O, A+ B ,:IAi+l}NZ@r?(J1lPJiJ$.
• “d_7J$H9kH7b9k"k4j:`Od_9k” (MarkovN6})r'ak.
Markov
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=.*tXHO 5. Bishop.=.*tX
Bishop.=.*tX
• 8_Z@OqN*Kror~?9P]NBz*K+D1kjJ,?(ilJ1lPJiJ$.
• A ∨ B NZ@O, A+ B NIAi,.j)D+Nps,Bz*K?(ilJ1lPJiJ$.
• Sf'O,lLK'aJ$.• 7+7,tX*P]OoK"k4j:`G?(ilk,WOJ$.
-
=.*tXHO)
• -B*tX (Kronecker, Hilbert)• DR*tX (Poincaré, Weyl, etc..)• >QgAtX (Brouwer, etc..)• F"*tX (Markov, etc..)• Bishop.=.*tX (Bishop, etc..)
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Z@H BHKra
INAN?jKIsJZ@,?(ilkY-+)
• A ∧B NZ@ (p, q)O ANZ@ pH B NZ@ q NZ";
NZ@ O ^?O H JiP NZ@
JiP NZ@ H$&ANZ"
NZ@O N$+JkZ@ b NZ@ XHQ99k,'
NZ@O N$+JkZ@ +ib7br3/,'
NZ@O jAhbN KP7F NZ@rV9,'
NZ@ O H NZ@ NZ"
3lO raHFPlk
N>QgAtXN@}Nt,r i,0}7?bNG
.>QgAtXdF"*tXN@}H7FQ$ilF$k
J< 1K=.*tXH@C?lg .N=.*tXrX93HK9k
CK djdj}O .N=.*tXK*1kbNG"k3HKmU;h
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Z@H BHKra
INAN?jKIsJZ@,?(ilkY-+)
• A ∧B NZ@ (p, q)O ANZ@ pH B NZ@ q NZ";• A ∨B NZ@ (i, p)O i = 0^?O 1H i = 0JiP ANZ@ p, i = 1JiP B NZ@ pH$&ANZ".
NZ@O N$+JkZ@ b NZ@ XHQ99k,'
NZ@O N$+JkZ@ +ib7br3/,'
NZ@O jAhbN KP7F NZ@rV9,'
NZ@ O H NZ@ NZ"
3lO raHFPlk
N>QgAtXN@}Nt,r i,0}7?bNG
.>QgAtXdF"*tXN@}H7FQ$ilF$k
J< 1K=.*tXH@C?lg .N=.*tXrX93HK9k
CK djdj}O .N=.*tXK*1kbNG"k3HKmU;h
-
Z@H BHKra
INAN?jKIsJZ@,?(ilkY-+)
• A ∧B NZ@ (p, q)O ANZ@ pH B NZ@ q NZ";• A ∨B NZ@ (i, p)O i = 0^?O 1H i = 0JiP ANZ@ p, i = 1JiP B NZ@ pH$&ANZ".
• A → B NZ@O, AN$+JkZ@ pb B NZ@ q XHQ99k,';
NZ@O N$+JkZ@ +ib7br3/,'
NZ@O jAhbN KP7F NZ@rV9,'
NZ@ O H NZ@ NZ"
3lO raHFPlk
N>QgAtXN@}Nt,r i,0}7?bNG
.>QgAtXdF"*tXN@}H7FQ$ilF$k
J< 1K=.*tXH@C?lg .N=.*tXrX93HK9k
CK djdj}O .N=.*tXK*1kbNG"k3HKmU;h
-
Z@H BHKra
INAN?jKIsJZ@,?(ilkY-+)
• A ∧B NZ@ (p, q)O ANZ@ pH B NZ@ q NZ";• A ∨B NZ@ (i, p)O i = 0^?O 1H i = 0JiP ANZ@ p, i = 1JiP B NZ@ pH$&ANZ".
• A → B NZ@O, AN$+JkZ@ pb B NZ@ q XHQ99k,';• ¬ANZ@O AN$+JkZ@ p+ib7br3/,';
NZ@O jAhbN KP7F NZ@rV9,'
NZ@ O H NZ@ NZ"
3lO raHFPlk
N>QgAtXN@}Nt,r i,0}7?bNG
.>QgAtXdF"*tXN@}H7FQ$ilF$k
J< 1K=.*tXH@C?lg .N=.*tXrX93HK9k
CK djdj}O .N=.*tXK*1kbNG"k3HKmU;h
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Z@H BHKra
INAN?jKIsJZ@,?(ilkY-+)
• A ∧B NZ@ (p, q)O ANZ@ pH B NZ@ q NZ";• A ∨B NZ@ (i, p)O i = 0^?O 1H i = 0JiP ANZ@ p, i = 1JiP B NZ@ pH$&ANZ".
• A → B NZ@O, AN$+JkZ@ pb B NZ@ q XHQ99k,';• ¬ANZ@O AN$+JkZ@ p+ib7br3/,';• ∀xA(x)NZ@O, (jAhbN) xKP7F A(x)NZ@rV9,';
NZ@ O H NZ@ NZ"
3lO raHFPlk
N>QgAtXN@}Nt,r i,0}7?bNG
.>QgAtXdF"*tXN@}H7FQ$ilF$k
J< 1K=.*tXH@C?lg .N=.*tXrX93HK9k
CK djdj}O .N=.*tXK*1kbNG"k3HKmU;h
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Z@H BHKra
INAN?jKIsJZ@,?(ilkY-+)
• A ∧B NZ@ (p, q)O ANZ@ pH B NZ@ q NZ";• A ∨B NZ@ (i, p)O i = 0^?O 1H i = 0JiP ANZ@ p, i = 1JiP B NZ@ pH$&ANZ".
• A → B NZ@O, AN$+JkZ@ pb B NZ@ q XHQ99k,';• ¬ANZ@O AN$+JkZ@ p+ib7br3/,';• ∀xA(x)NZ@O, (jAhbN) xKP7F A(x)NZ@rV9,';• ∃xA(x)NZ@ (d, p)O, dH A(d)NZ@ pNZ";
3lO raHFPlk
N>QgAtXN@}Nt,r i,0}7?bNG
.>QgAtXdF"*tXN@}H7FQ$ilF$k
J< 1K=.*tXH@C?lg .N=.*tXrX93HK9k
CK djdj}O .N=.*tXK*1kbNG"k3HKmU;h
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Z@H BHKra
INAN?jKIsJZ@,?(ilkY-+)
• A ∧B NZ@ (p, q)O ANZ@ pH B NZ@ q NZ";• A ∨B NZ@ (i, p)O i = 0^?O 1H i = 0JiP ANZ@ p, i = 1JiP B NZ@ pH$&ANZ".
• A → B NZ@O, AN$+JkZ@ pb B NZ@ q XHQ99k,';• ¬ANZ@O AN$+JkZ@ p+ib7br3/,';• ∀xA(x)NZ@O, (jAhbN) xKP7F A(x)NZ@rV9,';• ∃xA(x)NZ@ (d, p)O, dH A(d)NZ@ pNZ";3lO Brouwer-Heyting-KolmogorovraHFPlk.
BrouwerN>QgAtXN@}Nt,r Heytingi,0}7?bNG,
Bishop.>QgAtXdF"*tXN@}H7FQ$ilF$k.
J< 1K=.*tXH@C?lg .N=.*tXrX93HK9k
CK djdj}O .N=.*tXK*1kbNG"k3HKmU;h
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Z@H BHKra
INAN?jKIsJZ@,?(ilkY-+)
• A ∧B NZ@ (p, q)O ANZ@ pH B NZ@ q NZ";• A ∨B NZ@ (i, p)O i = 0^?O 1H i = 0JiP ANZ@ p, i = 1JiP B NZ@ pH$&ANZ".
• A → B NZ@O, AN$+JkZ@ pb B NZ@ q XHQ99k,';• ¬ANZ@O AN$+JkZ@ p+ib7br3/,';• ∀xA(x)NZ@O, (jAhbN) xKP7F A(x)NZ@rV9,';• ∃xA(x)NZ@ (d, p)O, dH A(d)NZ@ pNZ";3lO Brouwer-Heyting-KolmogorovraHFPlk.
BrouwerN>QgAtXN@}Nt,r Heytingi,0}7?bNG,
Bishop.>QgAtXdF"*tXN@}H7FQ$ilF$k.
J
-
Z@H?jN?6
ϕr$rhdjH9k.
• !Nh&K “jA”5l?8g ArM(k. (0 ∈ A) ∨ (1 ∈ A)O?+)
{x : (x = 1+D ϕ )∨(x = 0+D ¬ϕ )}
• BHKraGO (0 ∈ A) ∨ (1 ∈ A)NZ@O, ϕNZ@^?O?ZH&K?(ilkO:G"k.
7+7 #NH3mIAib?(ilF$J$NG
O?GOJ$
bAms 6GbJ$
-
Z@H?jN?6
ϕr$rhdjH9k.
• !Nh&K “jA”5l?8g ArM(k. (0 ∈ A) ∨ (1 ∈ A)O?+)
{x : (x = 1+D ϕ )∨(x = 0+D ¬ϕ )}
• BHKraGO (0 ∈ A) ∨ (1 ∈ A)NZ@O, ϕNZ@^?O?ZH&K?(ilkO:G"k.
• 7+7,#NH3mIAib?(ilF$J$NG, (0 ∈ A)∨ (1 ∈ A)O?GOJ$.
bAms 6GbJ$
-
Z@H?jN?6
ϕr$rhdjH9k.
• !Nh&K “jA”5l?8g ArM(k. (0 ∈ A) ∨ (1 ∈ A)O?+)
{x : (x = 1+D ϕ )∨(x = 0+D ¬ϕ )}
• BHKraGO (0 ∈ A) ∨ (1 ∈ A)NZ@O, ϕNZ@^?O?ZH&K?(ilkO:G"k.
• 7+7,#NH3mIAib?(ilF$J$NG, (0 ∈ A)∨ (1 ∈ A)O?GOJ$.
• bAms,6GbJ$.
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=.*tXHO 5. Bishop.=.*tX
Bishop.=.*tX
• 8_Z@OqN*Kror~?9P]NBz*K+D1kjJ,?(ilJ1lPJiJ$.
• A ∨ B NZ@O, A+ B NIAi,.j)D+Nps,Bz*K?(ilJ1lPJiJ$.
• Sf'O,lLK'aJ$.• 7+7,tX*P]OoK"k4j:`G?(ilk,WOJ$.
-
-!
• X∗ O X N5+iJk-BsN4N• |s|Gs sN95• snG sN n+ 1V\NWG (D^j s0O sNGiNWG)• s ∗ tO sH trDJ$@s,9JoA |u| = |s|+ |t|,
∀n < |s|(un = sn), ∀n < |u|(n ≥ |s| → sn = t(n− |s|))HJks u• s ⊂ tG sO tNZR,9JoA |s| < |t|, ∀n < |s|(sn = tn)r=9.
• +3tN5Bsr.j7c8zN.8z α, β, γ G=9.• αk O αN k − 1V\NWG• ᾱk O |s| = k, sn = αnJks
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Bz*JZ@NC
Bz*JZ@ · · · -B*J}!G-B~VbKT(kZ@
HGb@&+
H9k !NAN?j
O?+)
,?G"kJiP NZ@^?O NZ@,
?(ilk
7+7 + NIAi,.j)D+rN+ak
KOlLKO N9YFN`rA'C/9kJ0K}!OJ/ IA
i,.j)D+Npsb IAi+NZ@b?(ilkHOBiJ$
Bz*JZ@,J$
1MK !NAN?j O)
NGiN`+igVKA'C/r7F$CF qt`G ,PlP
vt`,9YF vt`G ,PlPqt`G9YF HJk
7+7 4FN`, Nlg 3&7?"k4j:`O_^iJ$
7?,CF 3N?jKbBz*JZ@OJ$
-
Bz*JZ@NC
Bz*JZ@ · · · -B*J}!G-B~VbKT(kZ@ (HGb@&+...)
H9k !NAN?j
O?+)
,?G"kJiP NZ@^?O NZ@,
?(ilk
7+7 + NIAi,.j)D+rN+ak
KOlLKO N9YFN`rA'C/9kJ0K}!OJ/ IA
i,.j)D+Npsb IAi+NZ@b?(ilkHOBiJ$
Bz*JZ@,J$
1MK !NAN?j O)
NGiN`+igVKA'C/r7F$CF qt`G ,PlP
vt`,9YF vt`G ,PlPqt`G9YF HJk
7+7 4FN`, Nlg 3&7?"k4j:`O_^iJ$
7?,CF 3N?jKbBz*JZ@OJ$
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Bz*JZ@NC
Bz*JZ@ · · · -B*J}!G-B~VbKT(kZ@ (HGb@&+...)• α : N → {0, 1}H9k. !NAN?j LPO (limited principle of omniscience)O?+)
∀n(αn = 0) ∨ ∃n(αn = 1)• A,?G"kJiP, ∀n(αn = 0)NZ@^?O ∃n(αn = 1)NZ@,?(ilk.
• 7+7, ∀n(αn = 0)+ ∃n(αn = 1)NIAi,.j)D+rN+akKOlLKO αN9YFN`rA'C/9kJ0K}!OJ/,IAi,.j)D+Npsb,IAi+NZ@b?(ilkHOBiJ$.
(Bz*JZ@,J$)
1MK !NAN?j O)
NGiN`+igVKA'C/r7F$CF qt`G ,PlP
vt`,9YF vt`G ,PlPqt`G9YF HJk
7+7 4FN`, Nlg 3&7?"k4j:`O_^iJ$
7?,CF 3N?jKbBz*JZ@OJ$
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Bz*JZ@NC
Bz*JZ@ · · · -B*J}!G-B~VbKT(kZ@ (HGb@&+...)• α : N → {0, 1}H9k. !NAN?j LPO (limited principle of omniscience)O?+)
∀n(αn = 0) ∨ ∃n(αn = 1)• A,?G"kJiP, ∀n(αn = 0)NZ@^?O ∃n(αn = 1)NZ@,?(ilk.
• 7+7, ∀n(αn = 0)+ ∃n(αn = 1)NIAi,.j)D+rN+akKOlLKO αN9YFN`rA'C/9kJ0K}!OJ/,IAi,.j)D+Npsb,IAi+NZ@b?(ilkHOBiJ$.
(Bz*JZ@,J$)
• 1MK,!NAN?j LLPO (lesser limited principle of omniscience)O)
∀m∀n(αm = αn = 1 → m = n) → ∀m(α(2m) = 0)∨∀n(α(2n+1) = 0)
• αNGiN`+igVKA'C/r7F$CF,qt`G 1,PlPvt`,9YF 0,vt`G 0,PlPqt`G9YF 0HJk.
• 7+7,4FN`, 0Nlg,3&7?"k4j:`O_^iJ$.7?,CF,3N?jKbBz*JZ@OJ$.
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MarkovN6}JI
1MK α : N → {0, 1}H9k. !NAN?jO?+)• ¬∃n(αn = 1) → ∀n(αn = 0)
• ¬∃n(αn = 1)NH-,$UN nKP7F, αn = [email protected]?,CF$UN nKP7F αn = 0. hCF B O?.
eH1MK? },dj
^?O
N6}
Gb HJk N?(}Oo+iJ$NG
?GOJ$ .
F"*tXGO3N6}O'ailF ?H5lF $?
-
MarkovN6}JI
1MK α : N → {0, 1}H9k. !NAN?jO?+)• ¬∃n(αn = 1) → ∀n(αn = 0)
• ¬∃n(αn = 1)NH-,$UN nKP7F, αn = [email protected]?,CF$UN nKP7F αn = 0. hCF B O?.
• ∀n(αn = 0) → ¬∃n(αn = 1)• eH1MK? (},dj).
^?O
N6}
Gb HJk N?(}Oo+iJ$NG
?GOJ$ .
F"*tXGO3N6}O'ailF ?H5lF $?
-
MarkovN6}JI
1MK α : N → {0, 1}H9k. !NAN?jO?+)• ¬∃n(αn = 1) → ∀n(αn = 0)
• ¬∃n(αn = 1)NH-,$UN nKP7F, αn = [email protected]?,CF$UN nKP7F αn = 0. hCF B O?.
• ∀n(αn = 0) → ¬∃n(αn = 1)• eH1MK? (},dj).
• ¬∀n(αn = 0) → ∃n(αn = 1)^?O¬¬∃n(αn = 0) → ∃n(αn = 1) (MarkovN6})• ¬∀n(αn = 0)Gb, αn = 1HJk nN?(}Oo+iJ$NG?GOJ$ (Bishop.)
• F"*tXGO3N6}O'ailF (?H5lF)$?.
-
+3t+i-}t,BtX
• =.*tX?/N)lGO,+3tH=NeNp\*Ji; (+, ·)dgx
-
BtCF)
BtN “jA”
• fX;db;G,&bN• -}tO[D9k5B.t (c: 13 = 0.3333333333 · · · )• 5}tO[D7J$5B.t (c:
√2 = 1.41421356237 · · · )
• Bt =-}t +5}t• gXG,&bN)
1. -}t4NN8gN DedekindZG
2. -}tN Cauchys
=.*tXGb,eN 1, 2KP~9k}!GjAG-k,,#sO Cauchy
sGjA9k3HK9k.
-
BtNjA
jA
• -}tNs 〈rn〉n G!Nror~?9bNr5'sH$&:
∀mn(|rm − rn| < m−1 + n−1).
5'sNVN1MX8 r!Gjak
5'sN4NN Khk&rBt Hjak
Je 5'sH=l,=9Btr1lk7FBt JIH=9
$/D+NXt }, 3li, G"k3HrN+ah
-
BtNjA
jA
• -}tNs 〈rn〉n G!Nror~?9bNr5'sH$&:
∀mn(|rm − rn| < m−1 + n−1).
• 5'sNVN1MX8 =R r!Gjak:
〈rl〉l =R 〈sl〉l ⇔ ∀m(|rm − sm| ≤2
m).
5'sN4NN Khk&rBt Hjak
Je 5'sH=l,=9Btr1lk7FBt JIH=9
$/D+NXt }, 3li, G"k3HrN+ah
-
BtNjA
jA
• -}tNs 〈rn〉n G!Nror~?9bNr5'sH$&:
∀mn(|rm − rn| < m−1 + n−1).
• 5'sNVN1MX8 =R r!Gjak:
〈rl〉l =R 〈sl〉l ⇔ ∀m(|rm − sm| ≤2
m).
• 5'sN4NN =R Khk&rBt RHjak.Je,5'sH=l,=9Btr1lk7FBt x = 〈xn〉n JIH=9.
$/D+NXt }, 3li, G"k3HrN+ah
-
BtNjA
jA
• -}tNs 〈rn〉n G!Nror~?9bNr5'sH$&:
∀mn(|rm − rn| < m−1 + n−1).
• 5'sNVN1MX8 =R r!Gjak:
〈rl〉l =R 〈sl〉l ⇔ ∀m(|rm − sm| ≤2
m).
• 5'sN4NN =R Khk&rBt RHjak.Je,5'sH=l,=9Btr1lk7FBt x = 〈xn〉n JIH=9.
• $/D+NXt (},: 3li, well-definedG"k3HrN+ah)
(x±R y)n = x2n ±Q y2n |x|n = |xn|max{x, y}n = maxxn, yn min{x, y}n = min{xn, yn}(x ·R y)n = x2kn ·Q y2kn, where k = max{|x|1 + 2, |y|1 + 2}
-
BteNgxHfSD=- 1. x
-
BteNgxHfSD=- 1. x
-
BteNgxHfSD=- 1. x
-
BteNgxHfSD=- 1. x
-
BteNgxHfSD=- 1. x
-
BtNfSD=- 2. x ≤R y ∨ y ≤R x
jA ∀n(− 1n≤Q xn)HJkBt x = 〈xn〉n rsi (non-negative)H9k.
Bt ReNX8 ≤R r!Gjak:
x ≤R y ⇐⇒ y − x,si
(mU) x ≤R y ⇔ x
-
BtNfSD=- 2. x ≤R y ∨ y ≤R x
jA ∀n(− 1n≤Q xn)HJkBt x = 〈xn〉n rsi (non-negative)H9k.
Bt ReNX8 ≤R r!Gjak:
x ≤R y ⇐⇒ y − x,si
(mU) x ≤R y ⇔ x
-
lg,1NF/KC/
3l^GG,!,.j)?J$3H,o+C?:
x
-
lg,1NF/KC/
3l^GG,!,.j)?J$3H,o+C?:
x
-
lg,1NF/KC/
3l^GG,!,.j)?J$3H,o+C?:
x
-
XtN"3-HfVMNj}
jA !r~?9Xt f : R → Rr"3XtH$&:
∀x ∈ R∀p ∈ Q+∃q ∈ Q+∀y ∈ R(|x− y| < q → |f(x)− f(y)| < p)
?j (fVMNj})
"3Xt f : [0, 1] → RH f(0)
-
XtN"3-HfVMNj}
jA !r~?9Xt f : R → Rr"3XtH$&:
∀x ∈ R∀p ∈ Q+∃q ∈ Q+∀y ∈ R(|x− y| < q → |f(x)− f(y)| < p)
?j (fVMNj})
"3Xt f : [0, 1] → RH f(0)
-
XtN"3-HfVMNj}
jA !r~?9Xt f : R → Rr"3XtH$&:
∀x ∈ R∀p ∈ Q+∃q ∈ Q+∀y ∈ R(|x− y| < q → |f(x)− f(y)| < p)
?j (fVMNj})
"3Xt f : [0, 1] → RH f(0)
-
=.*JfVMNj}
j} "3Xt f : [0, 1] → RH f(0)
-
=.*JfVMNj}
j} "3Xt f : [0, 1] → RH f(0)
-
=.*JfVMNj}
j} "3Xt f : [0, 1] → RH f(0)
-
s,ZH König’s Lemma
jA
• $UN t ∈ T H s ⊆ tKP7F s ∈ T HJk T ⊆ {0, 1}∗ rs,Z (binary tree)H$&.
• t ∈ T r T N^H$&.• T ,5B8gNH-,5Bs,ZH$&.• ∀n(ᾱ ∈ T )HJk α : N → {0, 1}r T NQ9H$&.• s ∈ {0, 1}∗ KP7F Ts = {t ∈ {0, 1}∗ : s ∗ t ∈ T} b^?s,ZG"k.
......
......
......
......
......
e: 04s,Z
-
s,ZH König’s Lemma
jA
• $UN t ∈ T H s ⊆ tKP7F s ∈ T HJk T ⊆ {0, 1}∗ rs,Z (binary tree)H$&.
• t ∈ T r T N^H$&.• T ,5B8gNH-,5Bs,ZH$&.• ∀n(ᾱ ∈ T )HJk α : N → {0, 1}r T NQ9H$&.• s ∈ {0, 1}∗ KP7F Ts = {t ∈ {0, 1}∗ : s ∗ t ∈ T} b^?s,ZG"k.
......
......
......
......
......
e: 04s,Z
-
s,ZH König’s Lemma
jA
• $UN t ∈ T H s ⊆ tKP7F s ∈ T HJk T ⊆ {0, 1}∗ rs,Z (binary tree)H$&.
• t ∈ T r T N^H$&.• T ,5B8gNH-,5Bs,ZH$&.• ∀n(ᾱ ∈ T )HJk α : N → {0, 1}r T NQ9H$&.• s ∈ {0, 1}∗ KP7F Ts = {t ∈ {0, 1}∗ : s ∗ t ∈ T} b^?s,ZG"k.
......
......
......
......
......
e: 04s,Z
-
s,ZH König’s Lemma
jA
• $UN t ∈ T H s ⊆ tKP7F s ∈ T HJk T ⊆ {0, 1}∗ rs,Z (binary tree)H$&.
• t ∈ T r T N^H$&.• T ,5B8gNH-,5Bs,ZH$&.• ∀n(ᾱ ∈ T )HJk α : N → {0, 1}r T NQ9H$&.• s ∈ {0, 1}∗ KP7F Ts = {t ∈ {0, 1}∗ : s ∗ t ∈ T} b^?s,ZG"k.
......
......
......
......
......
e: 04s,Z
-
Weak counter example
?j ϕ(n)H T ⊂ {0, 1}∗ r!GjA9k:ϕ(n) :=“π N=J.t8+K.th nL+i 99e"37? 9,"k”
T =
{
t ∈ {0, 1}∗ : t = 0n∧(∃k < nϕ(k)Ji=NG.N k Ovt)
t = 1n∧(∃k < nϕ(k)Ji=NG.N k Oqt)
}
• T O@i+K5BZ@,,Q9,"kH, ϕ(n)Ji=NG.NbNOvt(qt)NZ@,"k3HKJk.
E5*JtXGO KOQ9,8_9k, eNcOQ9N8_,=.
*KO(;J$3Hr(7F$k
3&7? ?c O "k$OGiKs2?MN>
0rHCF HFPlk
B] !N3H,NilF$k
j} O r3/
-
Weak counter example
?j ϕ(n)H T ⊂ {0, 1}∗ r!GjA9k:ϕ(n) :=“π N=J.t8+K.th nL+i 99e"37? 9,"k”
T =
{
t ∈ {0, 1}∗ : t = 0n∧(∃k < nϕ(k)Ji=NG.N k Ovt)
t = 1n∧(∃k < nϕ(k)Ji=NG.N k Oqt)
}
• T O@i+K5BZ@,,Q9,"kH, ϕ(n)Ji=NG.NbNOvt(qt)NZ@,"k3HKJk.
• E5*JtXGO T KOQ9,8_9k,,eNcOQ9N8_,=.*KO(;J$3Hr(7F$k.
3&7? ?c O "k$OGiKs2?MN>
0rHCF HFPlk
B] !N3H,NilF$k
j} O r3/
-
Weak counter example
?j ϕ(n)H T ⊂ {0, 1}∗ r!GjA9k:ϕ(n) :=“π N=J.t8+K.th nL+i 99e"37? 9,"k”
T =
{
t ∈ {0, 1}∗ : t = 0n∧(∃k < nϕ(k)Ji=NG.N k Ovt)
t = 1n∧(∃k < nϕ(k)Ji=NG.N k Oqt)
}
• T O@i+K5BZ@,,Q9,"kH, ϕ(n)Ji=NG.NbNOvt(qt)NZ@,"k3HKJk.
• E5*JtXGO T KOQ9,8_9k,,eNcOQ9N8_,=.*KO(;J$3Hr(7F$k.
• 3&7? “?c”O weak counter example"k$OGiKs2?MN>0rHCF Brouwerian counter exampleHFPlk.
B] !N3H,NilF$k
j} O r3/
-
Weak counter example
?j ϕ(n)H T ⊂ {0, 1}∗ r!GjA9k:ϕ(n) :=“π N=J.t8+K.th nL+i 99e"37? 9,"k”
T =
{
t ∈ {0, 1}∗ : t = 0n∧(∃k < nϕ(k)Ji=NG.N k Ovt)
t = 1n∧(∃k < nϕ(k)Ji=NG.N k Oqt)
}
• T O@i+K5BZ@,,Q9,"kH, ϕ(n)Ji=NG.NbNOvt(qt)NZ@,"k3HKJk.
• E5*JtXGO T KOQ9,8_9k,,eNcOQ9N8_,=.*KO(;J$3Hr(7F$k.
• 3&7? “?c”O weak counter example"k$OGiKs2?MN>0rHCF Brouwerian counter exampleHFPlk.
B],!N3H,NilF$k:
j} Weak König’s LemmaO LLPOr3/.
-
CantorN&Lt,j}HWeak König’s Lemma
jA
• BtN8g AG,$UNBt ε > 0KP7FBt y ∈(x− ε, x+ ε)∩A,8_9kH-, x ∈ AHJkbNrD8gH$&.
?j (CantorN&Lt,j})
BteND8gNs 〈Ci〉i KP7F,$UN iK"kBt x ∈⋂
k≤iCi ,8_9kH-,Bt x ∈
⋂
i∈NC ,8_9k.
dj ([0, 1]N4-&-)
$UN x ∈ [0, 1]H k ∈ NKP7F,"k j ≤ 2k ,8_7F, |x− j2k| ≤ 1
2k.
j} CantorN&Lt,j}OWeak König’s LemmaO1MG"k.
-
Weak König’s LemmaH Brouwer’s Fan Theorem
?j (Brouwer’s Fan Theorem)
s,Z T G,$UN α : N → {0, 1}KP7F ᾱn /∈ T HJk n,8_9lP,"k m ∈ N,8_7F$UN t ∈ T KP7F |t| < mG"k.
mU E5@}eGO O
NPvJNG 1MG"k
.=.*tXGO.j)?J$ F"*tXGO7br3/
>QgAtXGO O'ailF$?
KO ?Z ,?(ilF$?3HKmU
j} O r3/
-
Weak König’s LemmaH Brouwer’s Fan Theorem
?j (Brouwer’s Fan Theorem)
s,Z T G,$UN α : N → {0, 1}KP7F ᾱn /∈ T HJk n,8_9lP,"k m ∈ N,8_7F$UN t ∈ T KP7F |t| < mG"k.(mU)E5@}eGO, Brouwer’s Fan TheoremOWeak König’s Lemma
NPvJNG,1MG"k.
.=.*tXGO.j)?J$ F"*tXGO7br3/
>QgAtXGO O'ailF$?
KO ?Z ,?(ilF$?3HKmU
j} O r3/
-
Weak König’s LemmaH Brouwer’s Fan Theorem
?j (Brouwer’s Fan Theorem)
s,Z T G,$UN α : N → {0, 1}KP7F ᾱn /∈ T HJk n,8_9lP,"k m ∈ N,8_7F$UN t ∈ T KP7F |t| < mG"k.(mU)E5@}eGO, Brouwer’s Fan TheoremOWeak König’s Lemma
NPvJNG,1MG"k.
• Bishop.=.*tXGO.j)?J$. F"*tXGO7br3/.
>QgAtXGO O'ailF$?
KO ?Z ,?(ilF$?3HKmU
j} O r3/
-
Weak König’s LemmaH Brouwer’s Fan Theorem
?j (Brouwer’s Fan Theorem)
s,Z T G,$UN α : N → {0, 1}KP7F ᾱn /∈ T HJk n,8_9lP,"k m ∈ N,8_7F$UN t ∈ T KP7F |t| < mG"k.(mU)E5@}eGO, Brouwer’s Fan TheoremOWeak König’s Lemma
NPvJNG,1MG"k.
• Bishop.=.*tXGO.j)?J$. F"*tXGO7br3/.• >QgAtXGO, Brouwer’s Fan TheoremO'ailF$?.
(Weak König’s LemmaKO “?Z”,?(ilF$?3HKmU)
j} Weak König’s LemmaO Brouwer’s Fan Theoremr3/.
-
Brouwer’s Fan TheoremH Heine-BorelNo$j}
jA
• BtN8g AG,$UN x ∈ AKP7F"kBt ε > 0,8_7F(x− ε, x+ ε) ⊂ AHJkbNr+8gH$&.
8g KP7F +8gNs G$UN KP7F"k
,8_7F HJkbNr N+o$H$&
mU +o$H+8gNjA+i +o$O NAN8gN2H7Fh$
dj N4-&- FG
$UN H KP7F "k ,8_7F
?j No$j} N+o$KO-Bt,o$,8_9k
j} O No$j}H1MG"k
-
Brouwer’s Fan TheoremH Heine-BorelNo$j}
jA
• BtN8g AG,$UN x ∈ AKP7F"kBt ε > 0,8_7F(x− ε, x+ ε) ⊂ AHJkbNr+8gH$&.
• 8g X ⊆ RKP7F,+8gNs 〈Oi〉i G$UN x ∈ X KP7F"k i,8_7F x ∈ Oi HJkbNr X N+o$H$&.
(mU)+o$H+8gNjA+i,+o$O (a, b)NAN8gN2H7Fh$.
dj N4-&- FG
$UN H KP7F "k ,8_7F
?j No$j} N+o$KO-Bt,o$,8_9k
j} O No$j}H1MG"k
-
Brouwer’s Fan TheoremH Heine-BorelNo$j}
jA
• BtN8g AG,$UN x ∈ AKP7F"kBt ε > 0,8_7F(x− ε, x+ ε) ⊂ AHJkbNr+8gH$&.
• 8g X ⊆ RKP7F,+8gNs 〈Oi〉i G$UN x ∈ X KP7F"k i,8_7F x ∈ Oi HJkbNr X N+o$H$&.
(mU)+o$H+8gNjA+i,+o$O (a, b)NAN8gN2H7Fh$.
dj ([0, 1]N4-&-,FG)
$UN x ∈ [0, 1]H k ∈ NKP7F,"k j ≤ 2k ,8_7F, |x− j2k| ≤ 1
2k.
?j No$j} N+o$KO-Bt,o$,8_9k
j} O No$j}H1MG"k
-
Brouwer’s Fan TheoremH Heine-BorelNo$j}
jA
• BtN8g AG,$UN x ∈ AKP7F"kBt ε > 0,8_7F(x− ε, x+ ε) ⊂ AHJkbNr+8gH$&.
• 8g X ⊆ RKP7F,+8gNs 〈Oi〉i G$UN x ∈ X KP7F"k i,8_7F x ∈ Oi HJkbNr X N+o$H$&.
(mU)+o$H+8gNjA+i,+o$O (a, b)NAN8gN2H7Fh$.
dj ([0, 1]N4-&-,FG)
$UN x ∈ [0, 1]H k ∈ NKP7F,"k j ≤ 2k ,8_7F, |x− j2k| ≤ 1
2k.
?j (Heine-BorelNo$j}) [0, 1]N+o$KO-Bt,o$,8_9k.
j} O No$j}H1MG"k
-
Brouwer’s Fan TheoremH Heine-BorelNo$j}
jA
• BtN8g AG,$UN x ∈ AKP7F"kBt ε > 0,8_7F(x− ε, x+ ε) ⊂ AHJkbNr+8gH$&.
• 8g X ⊆ RKP7F,+8gNs 〈Oi〉i G$UN x ∈ X KP7F"k i,8_7F x ∈ Oi HJkbNr X N+o$H$&.
(mU)+o$H+8gNjA+i,+o$O (a, b)NAN8gN2H7Fh$.
dj ([0, 1]N4-&-,FG)
$UN x ∈ [0, 1]H k ∈ NKP7F,"k j ≤ 2k ,8_7F, |x− j2k| ≤ 1
2k.
?j (Heine-BorelNo$j}) [0, 1]N+o$KO-Bt,o$,8_9k.
j} Brouwer’s Fan TheoremO Heine-BorelNo$j}H1MG"k.
-
^Ha
CIP=⇒
WKL=⇒
LLPO⇐= ⇐=(1)
⇓6⇑ (1)⇓⇑HBT
=⇒BFT IVT⇐=
⇓BITV
.=.*tX
• CIP: CantorN&Lt,j}• WKL: Weak König’s Lemma• HBT: Heine-BorelNo$j}• BFT: Brouwer’s Fan Theorem• IVT:fVMNj}• BIV:=.*fVMNj}
1. soKe$bN@,,*rx}rW9k(DO#s(5J+C?t,r=9)
-
^Ha
CIP=⇒
WKL=⇒
LLPO⇐= ⇐=(1)
⇓6⇑ (1)⇓⇑HBT
=⇒BFT IVT⇐=
⇓BITV
Bishop.=.*tX
• CIP: CantorN&Lt,j}• WKL: Weak König’s Lemma• HBT: Heine-BorelNo$j}• BFT: Brouwer’s Fan Theorem• IVT:fVMNj}• BIV:=.*fVMNj}
1. soKe$bN@,,*rx}rW9k(DO#s(5J+C?t,r=9)
-
2M8%
TD. Troelstra and van Dalen, Constructivism in Mathematics Vol.1,
Elsevier, 1988
BB. Bishop and Bridges, Constructive Analysis, Springer, 1985
BR. Bridges and Richman, Varieties of Constructive Mathematics,
Cambridge University Press, Cambridge, 1987.
I. Ishihara, Constructive reverse mathematics: compactness properties,
In: L. Crosilla and P. Schuster eds., From Sets and Types to Analysis
and Topology: Towards Practicable Foundations for Constructive
Mathematics, Oxford Logic Guides 48, Oxford Univ. Press, 2005,
245-267.
0. 目次構成的数学とは?構成的数学とは? 1. 有限的数学構成的数学とは? 2. 可述的数学構成的数学とは? 3. 直観主義数学構成的数学とは? 4. 再帰的数学構成的数学とは 5. Bishop 流構成的数学構成的数学とは?証明と BHK 解釈証明と命題の真偽構成的数学とは 5. Bishop 流構成的数学記法実効的な証明の話Markov の原理など自然数から有理数, 実数へ実数って?実数の定義実数上の順序と比較可能性1. x