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Theorem nnm00 6793
Description: The product of two natural numbers is zero iff at least one of them is zero. (Contributed by Jim Kingdon, 11-Nov-2004.)
Assertion
Ref Expression
nnm00  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( ( A  .o  B )  =  (/)  <->  ( A  =  (/)  \/  B  =  (/) ) ) )

Proof of Theorem nnm00
StepHypRef Expression
1 simpl 109 . . . . . . 7  |-  ( ( A  =  (/)  /\  B  =  (/) )  ->  A  =  (/) )
2 simpl 109 . . . . . . 7  |-  ( ( A  =  (/)  /\  (/)  e.  B
)  ->  A  =  (/) )
31, 2jaoi 728 . . . . . 6  |-  ( ( ( A  =  (/)  /\  B  =  (/) )  \/  ( A  =  (/)  /\  (/)  e.  B ) )  ->  A  =  (/) )
43orcd 745 . . . . 5  |-  ( ( ( A  =  (/)  /\  B  =  (/) )  \/  ( A  =  (/)  /\  (/)  e.  B ) )  ->  ( A  =  (/)  \/  B  =  (/) ) )
54a1i 9 . . . 4  |-  ( ( ( A  e.  om  /\  B  e.  om )  /\  ( A  .o  B
)  =  (/) )  -> 
( ( ( A  =  (/)  /\  B  =  (/) )  \/  ( A  =  (/)  /\  (/)  e.  B
) )  ->  ( A  =  (/)  \/  B  =  (/) ) ) )
6 simpr 110 . . . . . . 7  |-  ( (
(/)  e.  A  /\  B  =  (/) )  ->  B  =  (/) )
76olcd 746 . . . . . 6  |-  ( (
(/)  e.  A  /\  B  =  (/) )  -> 
( A  =  (/)  \/  B  =  (/) ) )
87a1i 9 . . . . 5  |-  ( ( ( A  e.  om  /\  B  e.  om )  /\  ( A  .o  B
)  =  (/) )  -> 
( ( (/)  e.  A  /\  B  =  (/) )  -> 
( A  =  (/)  \/  B  =  (/) ) ) )
9 simplr 533 . . . . . . 7  |-  ( ( ( ( A  e. 
om  /\  B  e.  om )  /\  ( A  .o  B )  =  (/) )  /\  ( (/) 
e.  A  /\  (/)  e.  B
) )  ->  ( A  .o  B )  =  (/) )
10 nnmordi 6779 . . . . . . . . . . . . 13  |-  ( ( ( B  e.  om  /\  A  e.  om )  /\  (/)  e.  A )  ->  ( (/)  e.  B  ->  ( A  .o  (/) )  e.  ( A  .o  B
) ) )
1110expimpd 363 . . . . . . . . . . . 12  |-  ( ( B  e.  om  /\  A  e.  om )  ->  ( ( (/)  e.  A  /\  (/)  e.  B )  ->  ( A  .o  (/) )  e.  ( A  .o  B ) ) )
1211ancoms 268 . . . . . . . . . . 11  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( ( (/)  e.  A  /\  (/)  e.  B )  ->  ( A  .o  (/) )  e.  ( A  .o  B ) ) )
13 nnm0 6738 . . . . . . . . . . . . 13  |-  ( A  e.  om  ->  ( A  .o  (/) )  =  (/) )
1413adantr 276 . . . . . . . . . . . 12  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( A  .o  (/) )  =  (/) )
1514eleq1d 2307 . . . . . . . . . . 11  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( ( A  .o  (/) )  e.  ( A  .o  B )  <->  (/)  e.  ( A  .o  B ) ) )
1612, 15sylibd 149 . . . . . . . . . 10  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( ( (/)  e.  A  /\  (/)  e.  B )  ->  (/)  e.  ( A  .o  B ) ) )
1716adantr 276 . . . . . . . . 9  |-  ( ( ( A  e.  om  /\  B  e.  om )  /\  ( A  .o  B
)  =  (/) )  -> 
( ( (/)  e.  A  /\  (/)  e.  B )  ->  (/)  e.  ( A  .o  B ) ) )
1817imp 124 . . . . . . . 8  |-  ( ( ( ( A  e. 
om  /\  B  e.  om )  /\  ( A  .o  B )  =  (/) )  /\  ( (/) 
e.  A  /\  (/)  e.  B
) )  ->  (/)  e.  ( A  .o  B ) )
19 n0i 3527 . . . . . . . 8  |-  ( (/)  e.  ( A  .o  B
)  ->  -.  ( A  .o  B )  =  (/) )
2018, 19syl 14 . . . . . . 7  |-  ( ( ( ( A  e. 
om  /\  B  e.  om )  /\  ( A  .o  B )  =  (/) )  /\  ( (/) 
e.  A  /\  (/)  e.  B
) )  ->  -.  ( A  .o  B
)  =  (/) )
219, 20pm2.21dd 629 . . . . . 6  |-  ( ( ( ( A  e. 
om  /\  B  e.  om )  /\  ( A  .o  B )  =  (/) )  /\  ( (/) 
e.  A  /\  (/)  e.  B
) )  ->  ( A  =  (/)  \/  B  =  (/) ) )
2221ex 115 . . . . 5  |-  ( ( ( A  e.  om  /\  B  e.  om )  /\  ( A  .o  B
)  =  (/) )  -> 
( ( (/)  e.  A  /\  (/)  e.  B )  ->  ( A  =  (/)  \/  B  =  (/) ) ) )
238, 22jaod 729 . . . 4  |-  ( ( ( A  e.  om  /\  B  e.  om )  /\  ( A  .o  B
)  =  (/) )  -> 
( ( ( (/)  e.  A  /\  B  =  (/) )  \/  ( (/) 
e.  A  /\  (/)  e.  B
) )  ->  ( A  =  (/)  \/  B  =  (/) ) ) )
24 0elnn 4761 . . . . . . 7  |-  ( A  e.  om  ->  ( A  =  (/)  \/  (/)  e.  A
) )
25 0elnn 4761 . . . . . . 7  |-  ( B  e.  om  ->  ( B  =  (/)  \/  (/)  e.  B
) )
2624, 25anim12i 338 . . . . . 6  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( ( A  =  (/)  \/  (/)  e.  A )  /\  ( B  =  (/)  \/  (/)  e.  B ) ) )
27 anddi 833 . . . . . 6  |-  ( ( ( A  =  (/)  \/  (/)  e.  A )  /\  ( B  =  (/)  \/  (/)  e.  B
) )  <->  ( (
( A  =  (/)  /\  B  =  (/) )  \/  ( A  =  (/)  /\  (/)  e.  B ) )  \/  ( ( (/)  e.  A  /\  B  =  (/) )  \/  ( (/) 
e.  A  /\  (/)  e.  B
) ) ) )
2826, 27sylib 122 . . . . 5  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( ( ( A  =  (/)  /\  B  =  (/) )  \/  ( A  =  (/)  /\  (/)  e.  B
) )  \/  (
( (/)  e.  A  /\  B  =  (/) )  \/  ( (/)  e.  A  /\  (/)  e.  B ) ) ) )
2928adantr 276 . . . 4  |-  ( ( ( A  e.  om  /\  B  e.  om )  /\  ( A  .o  B
)  =  (/) )  -> 
( ( ( A  =  (/)  /\  B  =  (/) )  \/  ( A  =  (/)  /\  (/)  e.  B
) )  \/  (
( (/)  e.  A  /\  B  =  (/) )  \/  ( (/)  e.  A  /\  (/)  e.  B ) ) ) )
305, 23, 29mpjaod 730 . . 3  |-  ( ( ( A  e.  om  /\  B  e.  om )  /\  ( A  .o  B
)  =  (/) )  -> 
( A  =  (/)  \/  B  =  (/) ) )
3130ex 115 . 2  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( ( A  .o  B )  =  (/)  ->  ( A  =  (/)  \/  B  =  (/) ) ) )
32 oveq1 6082 . . . . . 6  |-  ( A  =  (/)  ->  ( A  .o  B )  =  ( (/)  .o  B
) )
33 nnm0r 6742 . . . . . 6  |-  ( B  e.  om  ->  ( (/) 
.o  B )  =  (/) )
3432, 33sylan9eqr 2293 . . . . 5  |-  ( ( B  e.  om  /\  A  =  (/) )  -> 
( A  .o  B
)  =  (/) )
3534ex 115 . . . 4  |-  ( B  e.  om  ->  ( A  =  (/)  ->  ( A  .o  B )  =  (/) ) )
3635adantl 277 . . 3  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( A  =  (/)  ->  ( A  .o  B
)  =  (/) ) )
37 oveq2 6083 . . . . . 6  |-  ( B  =  (/)  ->  ( A  .o  B )  =  ( A  .o  (/) ) )
3837, 13sylan9eqr 2293 . . . . 5  |-  ( ( A  e.  om  /\  B  =  (/) )  -> 
( A  .o  B
)  =  (/) )
3938ex 115 . . . 4  |-  ( A  e.  om  ->  ( B  =  (/)  ->  ( A  .o  B )  =  (/) ) )
4039adantr 276 . . 3  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( B  =  (/)  ->  ( A  .o  B
)  =  (/) ) )
4136, 40jaod 729 . 2  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( ( A  =  (/)  \/  B  =  (/) )  ->  ( A  .o  B )  =  (/) ) )
4231, 41impbid 129 1  |-  ( ( A  e.  om  /\  B  e.  om )  ->  ( ( A  .o  B )  =  (/)  <->  ( A  =  (/)  \/  B  =  (/) ) ) )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    /\ wa 104    <-> wb 105    \/ wo 720    = wceq 1402    e. wcel 2209   (/)c0 3520   omcom 4732  (class class class)co 6075    .o comu 6675
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 623  ax-in2 624  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-14 2212  ax-ext 2220  ax-coll 4241  ax-sep 4244  ax-nul 4254  ax-pow 4306  ax-pr 4341  ax-un 4573  ax-setind 4679  ax-iinf 4730
This theorem depends on definitions:  df-bi 117  df-3an 1011  df-tru 1405  df-fal 1408  df-nf 1514  df-sb 1816  df-eu 2089  df-mo 2090  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ne 2421  df-ral 2533  df-rex 2534  df-reu 2535  df-rab 2537  df-v 2823  df-sbc 3052  df-csb 3148  df-dif 3222  df-un 3224  df-in 3226  df-ss 3233  df-nul 3521  df-pw 3687  df-sn 3711  df-pr 3712  df-op 3714  df-uni 3931  df-int 3966  df-iun 4009  df-br 4126  df-opab 4188  df-mpt 4189  df-tr 4225  df-id 4433  df-iord 4506  df-on 4508  df-suc 4511  df-iom 4733  df-xp 4775  df-rel 4776  df-cnv 4777  df-co 4778  df-dm 4779  df-rn 4780  df-res 4781  df-ima 4782  df-iota 5332  df-fun 5374  df-fn 5375  df-f 5376  df-f1 5377  df-fo 5378  df-f1o 5379  df-fv 5380  df-ov 6078  df-oprab 6079  df-mpo 6080  df-1st 6364  df-2nd 6365  df-recs 6566  df-irdg 6631  df-oadd 6681  df-omul 6682
This theorem is referenced by:  enq0tr  7791  nqnq0pi  7795
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