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Theorem dom2 4386
Description: A mapping (first hypothesis) that is one-to-one (second hypothesis) implies its domain is dominated by its range. C and D can be read C(x) and D(y), as can be shown from their distinct variable conditions.
Hypotheses
Ref Expression
dom2.1 |- (x e. A -> C e. B)
dom2.2 |- ((x e. A /\ y e. A) -> (C = D <-> x = y))
Assertion
Ref Expression
dom2 |- (A e. R -> A ~<_ B)
Distinct variable groups:   x,y,A   x,B,y   y,C   x,D

Proof of Theorem dom2
StepHypRef Expression
1 eqid 1468 . 2 |- A = A
2 dom2.1 . . . 4 |- (x e. A -> C e. B)
32a1i 8 . . 3 |- (A = A -> (x e. A -> C e. B))
4 dom2.2 . . . 4 |- ((x e. A /\ y e. A) -> (C = D <-> x = y))
54a1i 8 . . 3 |- (A = A -> ((x e. A /\ y e. A) -> (C = D <-> x = y)))
63, 5dom2d 4385 . 2 |- (A = A -> (A e. R -> A ~<_ B))
71, 6ax-mp 7 1 |- (A e. R -> A ~<_ B)
Colors of variables: wff set class
Syntax hints:   -> wi 3   <-> wb 146   /\ wa 223   = wceq 953   e. wcel 955   class class class wbr 2609   ~<_ cdom 4349
This theorem is referenced by:  canth2 4464  limenpsi 4485  xpnnen 7441  znnen 7445
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 959  ax-gen 960  ax-8 961  ax-9 962  ax-10 963  ax-11 964  ax-12 965  ax-13 966  ax-14 967  ax-17 968  ax-4 970  ax-5o 972  ax-6o 975  ax-9o 1119  ax-10o 1136  ax-16 1206  ax-11o 1213  ax-ext 1452  ax-rep 2683  ax-sep 2693  ax-pow 2732  ax-pr 2769  ax-un 2857
This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225  df-ex 978  df-sb 1168  df-eu 1375  df-mo 1376  df-clab 1457  df-cleq 1462  df-clel 1465  df-ne 1579  df-ral 1641  df-rex 1642  df-v 1803  df-dif 2039  df-un 2040  df-in 2041  df-ss 2043  df-nul 2271  df-pw 2392  df-sn 2402  df-pr 2403  df-op 2406  df-uni 2494  df-br 2610  df-opab 2657  df-id 2824  df-xp 3174  df-rel 3175  df-cnv 3176  df-co 3177  df-dm 3178  df-rn 3179  df-res 3180  df-ima 3181  df-fun 3182  df-fn 3183  df-f 3184  df-f1 3185  df-fo 3186  df-f1o 3187  df-fv 3188  df-en 4351  df-dom 4352
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