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Theorem omcan 6453
Description: Left cancellation law for ordinal multiplication. Proposition 8.20 of [TakeutiZaring] p. 63 and its converse. (Contributed by NM, 14-Dec-2004.)
Assertion
Ref Expression
omcan  |-  ( ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  /\  (/)  e.  A )  ->  ( ( A  .o  B )  =  ( A  .o  C
)  <->  B  =  C
) )

Proof of Theorem omcan
StepHypRef Expression
1 omordi 6450 . . . . . . . . 9  |-  ( ( ( C  e.  On  /\  A  e.  On )  /\  (/)  e.  A )  ->  ( B  e.  C  ->  ( A  .o  B )  e.  ( A  .o  C ) ) )
21ex 425 . . . . . . . 8  |-  ( ( C  e.  On  /\  A  e.  On )  ->  ( (/)  e.  A  ->  ( B  e.  C  ->  ( A  .o  B
)  e.  ( A  .o  C ) ) ) )
32ancoms 441 . . . . . . 7  |-  ( ( A  e.  On  /\  C  e.  On )  ->  ( (/)  e.  A  ->  ( B  e.  C  ->  ( A  .o  B
)  e.  ( A  .o  C ) ) ) )
433adant2 979 . . . . . 6  |-  ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  ->  ( (/) 
e.  A  ->  ( B  e.  C  ->  ( A  .o  B )  e.  ( A  .o  C ) ) ) )
54imp 420 . . . . 5  |-  ( ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  /\  (/)  e.  A )  ->  ( B  e.  C  ->  ( A  .o  B )  e.  ( A  .o  C ) ) )
6 omordi 6450 . . . . . . . . 9  |-  ( ( ( B  e.  On  /\  A  e.  On )  /\  (/)  e.  A )  ->  ( C  e.  B  ->  ( A  .o  C )  e.  ( A  .o  B ) ) )
76ex 425 . . . . . . . 8  |-  ( ( B  e.  On  /\  A  e.  On )  ->  ( (/)  e.  A  ->  ( C  e.  B  ->  ( A  .o  C
)  e.  ( A  .o  B ) ) ) )
87ancoms 441 . . . . . . 7  |-  ( ( A  e.  On  /\  B  e.  On )  ->  ( (/)  e.  A  ->  ( C  e.  B  ->  ( A  .o  C
)  e.  ( A  .o  B ) ) ) )
983adant3 980 . . . . . 6  |-  ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  ->  ( (/) 
e.  A  ->  ( C  e.  B  ->  ( A  .o  C )  e.  ( A  .o  B ) ) ) )
109imp 420 . . . . 5  |-  ( ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  /\  (/)  e.  A )  ->  ( C  e.  B  ->  ( A  .o  C )  e.  ( A  .o  B ) ) )
115, 10orim12d 814 . . . 4  |-  ( ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  /\  (/)  e.  A )  ->  ( ( B  e.  C  \/  C  e.  B )  ->  (
( A  .o  B
)  e.  ( A  .o  C )  \/  ( A  .o  C
)  e.  ( A  .o  B ) ) ) )
1211con3d 127 . . 3  |-  ( ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  /\  (/)  e.  A )  ->  ( -.  (
( A  .o  B
)  e.  ( A  .o  C )  \/  ( A  .o  C
)  e.  ( A  .o  B ) )  ->  -.  ( B  e.  C  \/  C  e.  B ) ) )
13 omcl 6421 . . . . . . 7  |-  ( ( A  e.  On  /\  B  e.  On )  ->  ( A  .o  B
)  e.  On )
14 eloni 4295 . . . . . . 7  |-  ( ( A  .o  B )  e.  On  ->  Ord  ( A  .o  B
) )
1513, 14syl 17 . . . . . 6  |-  ( ( A  e.  On  /\  B  e.  On )  ->  Ord  ( A  .o  B ) )
16 omcl 6421 . . . . . . 7  |-  ( ( A  e.  On  /\  C  e.  On )  ->  ( A  .o  C
)  e.  On )
17 eloni 4295 . . . . . . 7  |-  ( ( A  .o  C )  e.  On  ->  Ord  ( A  .o  C
) )
1816, 17syl 17 . . . . . 6  |-  ( ( A  e.  On  /\  C  e.  On )  ->  Ord  ( A  .o  C ) )
19 ordtri3 4321 . . . . . 6  |-  ( ( Ord  ( A  .o  B )  /\  Ord  ( A  .o  C
) )  ->  (
( A  .o  B
)  =  ( A  .o  C )  <->  -.  (
( A  .o  B
)  e.  ( A  .o  C )  \/  ( A  .o  C
)  e.  ( A  .o  B ) ) ) )
2015, 18, 19syl2an 465 . . . . 5  |-  ( ( ( A  e.  On  /\  B  e.  On )  /\  ( A  e.  On  /\  C  e.  On ) )  -> 
( ( A  .o  B )  =  ( A  .o  C )  <->  -.  ( ( A  .o  B )  e.  ( A  .o  C )  \/  ( A  .o  C )  e.  ( A  .o  B ) ) ) )
21203impdi 1242 . . . 4  |-  ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  ->  (
( A  .o  B
)  =  ( A  .o  C )  <->  -.  (
( A  .o  B
)  e.  ( A  .o  C )  \/  ( A  .o  C
)  e.  ( A  .o  B ) ) ) )
2221adantr 453 . . 3  |-  ( ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  /\  (/)  e.  A )  ->  ( ( A  .o  B )  =  ( A  .o  C
)  <->  -.  ( ( A  .o  B )  e.  ( A  .o  C
)  \/  ( A  .o  C )  e.  ( A  .o  B
) ) ) )
23 eloni 4295 . . . . . 6  |-  ( B  e.  On  ->  Ord  B )
24 eloni 4295 . . . . . 6  |-  ( C  e.  On  ->  Ord  C )
25 ordtri3 4321 . . . . . 6  |-  ( ( Ord  B  /\  Ord  C )  ->  ( B  =  C  <->  -.  ( B  e.  C  \/  C  e.  B ) ) )
2623, 24, 25syl2an 465 . . . . 5  |-  ( ( B  e.  On  /\  C  e.  On )  ->  ( B  =  C  <->  -.  ( B  e.  C  \/  C  e.  B
) ) )
27263adant1 978 . . . 4  |-  ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  ->  ( B  =  C  <->  -.  ( B  e.  C  \/  C  e.  B )
) )
2827adantr 453 . . 3  |-  ( ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  /\  (/)  e.  A )  ->  ( B  =  C  <->  -.  ( B  e.  C  \/  C  e.  B ) ) )
2912, 22, 283imtr4d 261 . 2  |-  ( ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  /\  (/)  e.  A )  ->  ( ( A  .o  B )  =  ( A  .o  C
)  ->  B  =  C ) )
30 oveq2 5718 . 2  |-  ( B  =  C  ->  ( A  .o  B )  =  ( A  .o  C
) )
3129, 30impbid1 196 1  |-  ( ( ( A  e.  On  /\  B  e.  On  /\  C  e.  On )  /\  (/)  e.  A )  ->  ( ( A  .o  B )  =  ( A  .o  C
)  <->  B  =  C
) )
Colors of variables: wff set class
Syntax hints:   -. wn 5    -> wi 6    <-> wb 178    \/ wo 359    /\ wa 360    /\ w3a 939    = wceq 1619    e. wcel 1621   (/)c0 3362   Ord word 4284   Oncon0 4285  (class class class)co 5710    .o comu 6363
This theorem is referenced by:  omword  6454  fin1a2lem4  7913
This theorem was proved from axioms:  ax-1 7  ax-2 8  ax-3 9  ax-mp 10  ax-5 1533  ax-6 1534  ax-7 1535  ax-gen 1536  ax-8 1623  ax-11 1624  ax-13 1625  ax-14 1626  ax-17 1628  ax-12o 1664  ax-10 1678  ax-9 1684  ax-4 1692  ax-16 1926  ax-ext 2234  ax-rep 4028  ax-sep 4038  ax-nul 4046  ax-pr 4108  ax-un 4403
This theorem depends on definitions:  df-bi 179  df-or 361  df-an 362  df-3or 940  df-3an 941  df-tru 1315  df-ex 1538  df-nf 1540  df-sb 1883  df-eu 2118  df-mo 2119  df-clab 2240  df-cleq 2246  df-clel 2249  df-nfc 2374  df-ne 2414  df-ral 2513  df-rex 2514  df-reu 2515  df-rab 2516  df-v 2729  df-sbc 2922  df-csb 3010  df-dif 3081  df-un 3083  df-in 3085  df-ss 3089  df-pss 3091  df-nul 3363  df-if 3471  df-pw 3532  df-sn 3550  df-pr 3551  df-tp 3552  df-op 3553  df-uni 3728  df-iun 3805  df-br 3921  df-opab 3975  df-mpt 3976  df-tr 4011  df-eprel 4198  df-id 4202  df-po 4207  df-so 4208  df-fr 4245  df-we 4247  df-ord 4288  df-on 4289  df-lim 4290  df-suc 4291  df-om 4548  df-xp 4594  df-rel 4595  df-cnv 4596  df-co 4597  df-dm 4598  df-rn 4599  df-res 4600  df-ima 4601  df-fun 4602  df-fn 4603  df-f 4604  df-f1 4605  df-fo 4606  df-f1o 4607  df-fv 4608  df-ov 5713  df-oprab 5714  df-mpt2 5715  df-recs 6274  df-rdg 6309  df-oadd 6369  df-omul 6370
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