Theorem subeqrev 8274

Description: Reverse the order of subtraction in an equality. (Contributed by Scott Fenton, 8-Jul-2013.)

Assertion

Ref	Expression
subeqrev	|- ( ( ( A e. CC /\ B e. CC ) /\ ( C e. CC /\ D e. CC ) ) -> ( ( A - B ) = ( C - D ) <-> ( B - A ) = ( D - C ) ) )

Proof of Theorem subeqrev

Step	Hyp	Ref	Expression
1		subcl 8097	. . 3 |- ( ( A e. CC /\ B e. CC ) -> ( A - B ) e. CC )
2		subcl 8097	. . 3 |- ( ( C e. CC /\ D e. CC ) -> ( C - D ) e. CC )
3		neg11 8149	. . 3 |- ( ( ( A - B ) e. CC /\ ( C - D ) e. CC ) -> ( -u ( A - B ) = -u ( C - D ) <-> ( A - B ) = ( C - D ) ) )
4	1, 2, 3	syl2an 287	. 2 |- ( ( ( A e. CC /\ B e. CC ) /\ ( C e. CC /\ D e. CC ) ) -> ( -u ( A - B ) = -u ( C - D ) <-> ( A - B ) = ( C - D ) ) )
5		negsubdi2 8157	. . 3 |- ( ( A e. CC /\ B e. CC ) -> -u ( A - B ) = ( B - A ) )
6		negsubdi2 8157	. . 3 |- ( ( C e. CC /\ D e. CC ) -> -u ( C - D ) = ( D - C ) )
7	5, 6	eqeqan12d 2181	. 2 |- ( ( ( A e. CC /\ B e. CC ) /\ ( C e. CC /\ D e. CC ) ) -> ( -u ( A - B ) = -u ( C - D ) <-> ( B - A ) = ( D - C ) ) )
8	4, 7	bitr3d 189	1 |- ( ( ( A e. CC /\ B e. CC ) /\ ( C e. CC /\ D e. CC ) ) -> ( ( A - B ) = ( C - D ) <-> ( B - A ) = ( D - C ) ) )

Syntax hints:   -> wi 4   /\ wa 103   <-> wb 104   = wceq 1343   e. wcel 2136  (class class class)co 5842   CCcc 7751   - cmin 8069   -ucneg 8070

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 604  ax-in2 605  ax-io 699  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-14 2139  ax-ext 2147  ax-sep 4100  ax-pow 4153  ax-pr 4187  ax-setind 4514  ax-resscn 7845  ax-1cn 7846  ax-icn 7848  ax-addcl 7849  ax-addrcl 7850  ax-mulcl 7851  ax-addcom 7853  ax-addass 7855  ax-distr 7857  ax-i2m1 7858  ax-0id 7861  ax-rnegex 7862  ax-cnre 7864

This theorem depends on definitions:  df-bi 116  df-3an 970  df-tru 1346  df-fal 1349  df-nf 1449  df-sb 1751  df-eu 2017  df-mo 2018  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-ne 2337  df-ral 2449  df-rex 2450  df-reu 2451  df-rab 2453  df-v 2728  df-sbc 2952  df-dif 3118  df-un 3120  df-in 3122  df-ss 3129  df-pw 3561  df-sn 3582  df-pr 3583  df-op 3585  df-uni 3790  df-br 3983  df-opab 4044  df-id 4271  df-xp 4610  df-rel 4611  df-cnv 4612  df-co 4613  df-dm 4614  df-iota 5153  df-fun 5190  df-fv 5196  df-riota 5798  df-ov 5845  df-oprab 5846  df-mpo 5847  df-sub 8071  df-neg 8072

This theorem is referenced by: (None)