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Theorem canth 3898
Description: No set A is equinumerous to its power set (Cantor's theorem), i.e. no function can map A it onto its power set. Compare Theorem 6B(b) of [Enderton] p. 132. For the equinumerosity version, see canth2 4470. Note that A must be a set: this theorem does not hold when A is too large to be a set; see ncanth 3899 for a counterexample. (Use nex 1099 if you want the form -. E.ff:A-onto->P~A.)
Hypothesis
Ref Expression
canth.1 |- A e. V
Assertion
Ref Expression
canth |- -. F:A-onto->P~A

Proof of Theorem canth
StepHypRef Expression
1 forn 3665 . 2 |- (F:A-onto->P~A -> ran F = P~A)
2 fof 3663 . . 3 |- (F:A-onto->P~A -> F:A-->P~A)
3 id 59 . . . . . . . . . 10 |- (x = y -> x = y)
4 fveq2 3715 . . . . . . . . . 10 |- (x = y -> (F` x) = (F` y))
53, 4eleq12d 1539 . . . . . . . . 9 |- (x = y -> (x e. (F` x) <-> y e. (F` y)))
65negbid 610 . . . . . . . 8 |- (x = y -> (-. x e. (F` x) <-> -. y e. (F` y)))
76elrab 1901 . . . . . . 7 |- (y e. {x e. A | -. x e. (F` x)} <-> (y e. A /\ -. y e. (F` y)))
87baibr 685 . . . . . 6 |- (y e. A -> (-. y e. (F` y) <-> y e. {x e. A | -. x e. (F` x)}))
9 nbbn 660 . . . . . . 7 |- ((-. y e. (F` y) <-> y e. {x e. A | -. x e. (F` x)}) <-> -. (y e. (F` y) <-> y e. {x e. A | -. x e. (F` x)}))
10 eleq2 1532 . . . . . . . 8 |- ((F` y) = {x e. A | -. x e. (F` x)} -> (y e. (F` y) <-> y e. {x e. A | -. x e. (F` x)}))
1110con3i 98 . . . . . . 7 |- (-. (y e. (F` y) <-> y e. {x e. A | -. x e. (F` x)}) -> -. (F` y) = {x e. A | -. x e. (F` x)})
129, 11sylbi 199 . . . . . 6 |- ((-. y e. (F` y) <-> y e. {x e. A | -. x e. (F` x)}) -> -. (F` y) = {x e. A | -. x e. (F` x)})
138, 12syl 10 . . . . 5 |- (y e. A -> -. (F` y) = {x e. A | -. x e. (F` x)})
1413rgen 1695 . . . 4 |- A.y e. A -. (F` y) = {x e. A | -. x e. (F` x)}
15 ffn 3619 . . . . . . 7 |- (F:A-->P~A -> F Fn A)
16 fvelrnb 3751 . . . . . . . 8 |- (F Fn A -> ({x e. A | -. x e. (F` x)} e. ran F <-> E.y e. A (F` y) = {x e. A | -. x e. (F` x)}))
1716biimpd 153 . . . . . . 7 |- (F Fn A -> ({x e. A | -. x e. (F` x)} e. ran F -> E.y e. A (F` y) = {x e. A | -. x e. (F` x)}))
1815, 17syl 10 . . . . . 6 |- (F:A-->P~A -> ({x e. A | -. x e. (F` x)} e. ran F -> E.y e. A (F` y) = {x e. A | -. x e. (F` x)}))
1918con3d 95 . . . . 5 |- (F:A-->P~A -> (-. E.y e. A (F` y) = {x e. A | -. x e. (F` x)} -> -. {x e. A | -. x e. (F` x)} e. ran F))
20 ralnex 1650 . . . . 5 |- (A.y e. A -. (F` y) = {x e. A | -. x e. (F` x)} <-> -. E.y e. A (F` y) = {x e. A | -. x e. (F` x)})
2119, 20syl5ib 206 . . . 4 |- (F:A-->P~A -> (A.y e. A -. (F` y) = {x e. A | -. x e. (F` x)} -> -. {x e. A | -. x e. (F` x)} e. ran F))
2214, 21mpi 44 . . 3 |- (F:A-->P~A -> -. {x e. A | -. x e. (F` x)} e. ran F)
23 ssrab2 2127 . . . . . 6 |- {x e. A | -. x e. (F` x)} (_ A
24 canth.1 . . . . . . . 8 |- A e. V
2524rabex 2720 . . . . . . 7 |- {x e. A | -. x e. (F` x)} e. V
2625elpw 2400 . . . . . 6 |- ({x e. A | -. x e. (F` x)} e. P~A <-> {x e. A | -. x e. (F` x)} (_ A)
2723, 26mpbir 190 . . . . 5 |- {x e. A | -. x e. (F` x)} e. P~A
28 eleq2 1532 . . . . 5 |- (ran F = P~A -> ({x e. A | -. x e. (F` x)} e. ran F <-> {x e. A | -. x e. (F` x)} e. P~A))
2927, 28mpbiri 194 . . . 4 |- (ran F = P~A -> {x e. A | -. x e. (F` x)} e. ran F)
3029con3i 98 . . 3 |- (-. {x e. A | -. x e. (F` x)} e. ran F -> -. ran F = P~A)
312, 22, 303syl 20 . 2 |- (F:A-onto->P~A -> -. ran F = P~A)
321, 31pm2.65i 135 1 |- -. F:A-onto->P~A
Colors of variables: wff set class
Syntax hints:  -. wn 2   -> wi 3   <-> wb 146   = wceq 954   e. wcel 956  A.wral 1642  E.wrex 1643  {crab 1645  Vcvv 1807   (_ wss 2043  P~cpw 2397  ran crn 3166   Fn wfn 3172  -->wf 3173  -onto->wfo 3175  ` cfv 3177
This theorem is referenced by:  canth2 4470
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 960  ax-gen 961  ax-8 962  ax-10 964  ax-11 965  ax-12 966  ax-13 967  ax-14 968  ax-17 969  ax-4 971  ax-5o 973  ax-6o 976  ax-9o 1121  ax-10o 1138  ax-16 1208  ax-11o 1216  ax-ext 1457  ax-sep 2698  ax-pow 2737  ax-pr 2774  ax-un 2861
This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225  df-ex 979  df-sb 1170  df-eu 1380  df-mo 1381  df-clab 1462  df-cleq 1467  df-clel 1470  df-ne 1584  df-ral 1646  df-rex 1647  df-rab 1649  df-v 1808  df-dif 2045  df-un 2046  df-in 2047  df-ss 2049  df-nul 2277  df-pw 2398  df-sn 2408  df-pr 2409  df-op 2412  df-uni 2499  df-br 2615  df-opab 2662  df-id 2830  df-xp 3179  df-cnv 3181  df-co 3182  df-dm 3183  df-rn 3184  df-res 3185  df-ima 3186  df-fun 3187  df-fn 3188  df-f 3189  df-fo 3191  df-fv 3193
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