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Theorem subval 8508
Description: Value of subtraction, which is the (unique) element  x such that  B  +  x  =  A. (Contributed by NM, 4-Aug-2007.) (Revised by Mario Carneiro, 2-Nov-2013.)
Assertion
Ref Expression
subval  |-  ( ( A  e.  CC  /\  B  e.  CC )  ->  ( A  -  B
)  =  ( iota_ x  e.  CC  ( B  +  x )  =  A ) )
Distinct variable groups:    x, A    x, B

Proof of Theorem subval
Dummy variables  y  z are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 negeu 8507 . . . 4  |-  ( ( B  e.  CC  /\  A  e.  CC )  ->  E! x  e.  CC  ( B  +  x
)  =  A )
2 riotacl 6044 . . . 4  |-  ( E! x  e.  CC  ( B  +  x )  =  A  ->  ( iota_ x  e.  CC  ( B  +  x )  =  A )  e.  CC )
31, 2syl 14 . . 3  |-  ( ( B  e.  CC  /\  A  e.  CC )  ->  ( iota_ x  e.  CC  ( B  +  x
)  =  A )  e.  CC )
43ancoms 268 . 2  |-  ( ( A  e.  CC  /\  B  e.  CC )  ->  ( iota_ x  e.  CC  ( B  +  x
)  =  A )  e.  CC )
5 eqeq2 2248 . . . 4  |-  ( y  =  A  ->  (
( z  +  x
)  =  y  <->  ( z  +  x )  =  A ) )
65riotabidv 6030 . . 3  |-  ( y  =  A  ->  ( iota_ x  e.  CC  (
z  +  x )  =  y )  =  ( iota_ x  e.  CC  ( z  +  x
)  =  A ) )
7 oveq1 6082 . . . . 5  |-  ( z  =  B  ->  (
z  +  x )  =  ( B  +  x ) )
87eqeq1d 2247 . . . 4  |-  ( z  =  B  ->  (
( z  +  x
)  =  A  <->  ( B  +  x )  =  A ) )
98riotabidv 6030 . . 3  |-  ( z  =  B  ->  ( iota_ x  e.  CC  (
z  +  x )  =  A )  =  ( iota_ x  e.  CC  ( B  +  x
)  =  A ) )
10 df-sub 8489 . . 3  |-  -  =  ( y  e.  CC ,  z  e.  CC  |->  ( iota_ x  e.  CC  ( z  +  x
)  =  y ) )
116, 9, 10ovmpog 6213 . 2  |-  ( ( A  e.  CC  /\  B  e.  CC  /\  ( iota_ x  e.  CC  ( B  +  x )  =  A )  e.  CC )  ->  ( A  -  B )  =  (
iota_ x  e.  CC  ( B  +  x
)  =  A ) )
124, 11mpd3an3 1379 1  |-  ( ( A  e.  CC  /\  B  e.  CC )  ->  ( A  -  B
)  =  ( iota_ x  e.  CC  ( B  +  x )  =  A ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104    = wceq 1402    e. wcel 2209   E!wreu 2530   iota_crio 6027  (class class class)co 6075   CCcc 8167    + caddc 8172    - cmin 8487
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-sep 4244  ax-pow 4306  ax-pr 4341  ax-setind 4679  ax-resscn 8261  ax-1cn 8262  ax-icn 8264  ax-addcl 8265  ax-addrcl 8266  ax-mulcl 8267  ax-addcom 8269  ax-addass 8271  ax-distr 8273  ax-i2m1 8274  ax-0id 8277  ax-rnegex 8278  ax-cnre 8280
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-dif 3222  df-un 3224  df-in 3226  df-ss 3233  df-pw 3687  df-sn 3711  df-pr 3712  df-op 3714  df-uni 3931  df-br 4126  df-opab 4188  df-id 4433  df-xp 4775  df-rel 4776  df-cnv 4777  df-co 4778  df-dm 4779  df-iota 5332  df-fun 5374  df-fv 5380  df-riota 6028  df-ov 6078  df-oprab 6079  df-mpo 6080  df-sub 8489
This theorem is referenced by:  subcl  8515  subf  8518  subadd  8519
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