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Theorem discrlem3 6588
Description: Lemma for discriminant theorem.
Hypotheses
Ref Expression
discrlem.1 |- A e. RR
discrlem.2 |- B e. RR
discrlem.3 |- C e. RR
discrlem3.4 |- D = ((C + 1) / -uB)
discrlem3.5 |- (D e. RR -> 0 <_ (((A x. (D^2)) + (B x. D)) + C))
Assertion
Ref Expression
discrlem3 |- (0 = A -> ((B^2) - (4 x. (A x. C))) <_ 0)

Proof of Theorem discrlem3
StepHypRef Expression
1 discrlem.3 . . . . . . . . . 10 |- C e. RR
21ltp1 5769 . . . . . . . . 9 |- C < (C + 1)
3 df-ne 1579 . . . . . . . . . . 11 |- (B =/= 0 <-> -. B = 0)
4 discrlem.2 . . . . . . . . . . . . 13 |- B e. RR
54recn 5286 . . . . . . . . . . . 12 |- B e. CC
65negne0 5763 . . . . . . . . . . 11 |- (B =/= 0 <-> -uB =/= 0)
73, 6bitr3 175 . . . . . . . . . 10 |- (-. B = 0 <-> -uB =/= 0)
8 1re 5407 . . . . . . . . . . . . . . . . . . . 20 |- 1 e. RR
91, 8readdcl 5306 . . . . . . . . . . . . . . . . . . 19 |- (C + 1) e. RR
104renegcl 5388 . . . . . . . . . . . . . . . . . . 19 |- -uB e. RR
119, 10redivclz 5755 . . . . . . . . . . . . . . . . . 18 |- (-uB =/= 0 -> ((C + 1) / -uB) e. RR)
12 discrlem3.4 . . . . . . . . . . . . . . . . . 18 |- D = ((C + 1) / -uB)
1311, 12syl5eqel 1544 . . . . . . . . . . . . . . . . 17 |- (-uB =/= 0 -> D e. RR)
14 discrlem3.5 . . . . . . . . . . . . . . . . 17 |- (D e. RR -> 0 <_ (((A x. (D^2)) + (B x. D)) + C))
1513, 14syl 10 . . . . . . . . . . . . . . . 16 |- (-uB =/= 0 -> 0 <_ (((A x. (D^2)) + (B x. D)) + C))
1615adantr 389 . . . . . . . . . . . . . . 15 |- ((-uB =/= 0 /\ 0 = A) -> 0 <_ (((A x. (D^2)) + (B x. D)) + C))
17 opreq1 3953 . . . . . . . . . . . . . . . . . . . 20 |- (0 = A -> (0 x. (D^2)) = (A x. (D^2)))
1817eqcomd 1472 . . . . . . . . . . . . . . . . . . 19 |- (0 = A -> (A x. (D^2)) = (0 x. (D^2)))
1913recnd 5287 . . . . . . . . . . . . . . . . . . . 20 |- (-uB =/= 0 -> D e. CC)
20 sqclt 6542 . . . . . . . . . . . . . . . . . . . 20 |- (D e. CC -> (D^2) e. CC)
21 mul02t 5416 . . . . . . . . . . . . . . . . . . . 20 |- ((D^2) e. CC -> (0 x. (D^2)) = 0)
2219, 20, 213syl 20 . . . . . . . . . . . . . . . . . . 19 |- (-uB =/= 0 -> (0 x. (D^2)) = 0)
2318, 22sylan9eqr 1521 . . . . . . . . . . . . . . . . . 18 |- ((-uB =/= 0 /\ 0 = A) -> (A x. (D^2)) = 0)
2423opreq1d 3960 . . . . . . . . . . . . . . . . 17 |- ((-uB =/= 0 /\ 0 = A) -> ((A x. (D^2)) + (B x. D)) = (0 + (B x. D)))
2513, 4jctil 292 . . . . . . . . . . . . . . . . . . . . 21 |- (-uB =/= 0 -> (B e. RR /\ D e. RR))
26 axmulrcl 5246 . . . . . . . . . . . . . . . . . . . . 21 |- ((B e. RR /\ D e. RR) -> (B x. D) e. RR)
2725, 26syl 10 . . . . . . . . . . . . . . . . . . . 20 |- (-uB =/= 0 -> (B x. D) e. RR)
2827recnd 5287 . . . . . . . . . . . . . . . . . . 19 |- (-uB =/= 0 -> (B x. D) e. CC)
29 addid2t 5301 . . . . . . . . . . . . . . . . . . 19 |- ((B x. D) e. CC -> (0 + (B x. D)) = (B x. D))
3028, 29syl 10 . . . . . . . . . . . . . . . . . 18 |- (-uB =/= 0 -> (0 + (B x. D)) = (B x. D))
3130adantr 389 . . . . . . . . . . . . . . . . 17 |- ((-uB =/= 0 /\ 0 = A) -> (0 + (B x. D)) = (B x. D))
3224, 31eqtrd 1499 . . . . . . . . . . . . . . . 16 |- ((-uB =/= 0 /\ 0 = A) -> ((A x. (D^2)) + (B x. D)) = (B x. D))
3332opreq1d 3960 . . . . . . . . . . . . . . 15 |- ((-uB =/= 0 /\ 0 = A) -> (((A x. (D^2)) + (B x. D)) + C) = ((B x. D) + C))
3416, 33breqtrd 2629 . . . . . . . . . . . . . 14 |- ((-uB =/= 0 /\ 0 = A) -> 0 <_ ((B x. D) + C))
35 0re 5412 . . . . . . . . . . . . . . . . 17 |- 0 e. RR
36 lesubadd2t 5604 . . . . . . . . . . . . . . . . 17 |- ((0 e. RR /\ (B x. D) e. RR /\ C e. RR) -> ((0 - (B x. D)) <_ C <-> 0 <_ ((B x. D) + C)))
3735, 1, 36mp3an13 904 . . . . . . . . . . . . . . . 16 |- ((B x. D) e. RR -> ((0 - (B x. D)) <_ C <-> 0 <_ ((B x. D) + C)))
3825, 26, 373syl 20 . . . . . . . . . . . . . . 15 |- (-uB =/= 0 -> ((0 - (B x. D)) <_ C <-> 0 <_ ((B x. D) + C)))
3938adantr 389 . . . . . . . . . . . . . 14 |- ((-uB =/= 0 /\ 0 = A) -> ((0 - (B x. D)) <_ C <-> 0 <_ ((B x. D) + C)))
4034, 39mpbird 196 . . . . . . . . . . . . 13 |- ((-uB =/= 0 /\ 0 = A) -> (0 - (B x. D)) <_ C)
41 recnt 5285 . . . . . . . . . . . . . . . . . . . 20 |- (B e. RR -> B e. CC)
42 recnt 5285 . . . . . . . . . . . . . . . . . . . 20 |- (D e. RR -> D e. CC)
4341, 42anim12i 333 . . . . . . . . . . . . . . . . . . 19 |- ((B e. RR /\ D e. RR) -> (B e. CC /\ D e. CC))
44 mulneg1t 5423 . . . . . . . . . . . . . . . . . . 19 |- ((B e. CC /\ D e. CC) -> (-uB x. D) = -u(B x. D))
4525, 43, 443syl 20 . . . . . . . . . . . . . . . . . 18 |- (-uB =/= 0 -> (-uB x. D) = -u(B x. D))
4645eqcomd 1472 . . . . . . . . . . . . . . . . 17 |- (-uB =/= 0 -> -u(B x. D) = (-uB x. D))
47 df-neg 5330 . . . . . . . . . . . . . . . . 17 |- -u(B x. D) = (0 - (B x. D))
4812opreq2i 3957 . . . . . . . . . . . . . . . . 17 |- (-uB x. D) = (-uB x. ((C + 1) / -uB))
4946, 47, 483eqtr3g 1522 . . . . . . . . . . . . . . . 16 |- (-uB =/= 0 -> (0 - (B x. D)) = (-uB x. ((C + 1) / -uB)))
505negcl 5341 . . . . . . . . . . . . . . . . 17 |- -uB e. CC
519recn 5286 . . . . . . . . . . . . . . . . 17 |- (C + 1) e. CC
5250, 51divcan2z 5688 . . . . . . . . . . . . . . . 16 |- (-uB =/= 0 -> (-uB x. ((C + 1) / -uB)) = (C + 1))
5349, 52eqtrd 1499 . . . . . . . . . . . . . . 15 |- (-uB =/= 0 -> (0 - (B x. D)) = (C + 1))
5453breq1d 2619 . . . . . . . . . . . . . 14 |- (-uB =/= 0 -> ((0 - (B x. D)) <_ C <-> (C + 1) <_ C))
5554adantr 389 . . . . . . . . . . . . 13 |- ((-uB =/= 0 /\ 0 = A) -> ((0 - (B x. D)) <_ C <-> (C + 1) <_ C))
5640, 55mpbid 195 . . . . . . . . . . . 12 |- ((-uB =/= 0 /\ 0 = A) -> (C + 1) <_ C)
579, 1lenlt 5551 . . . . . . . . . . . 12 |- ((C + 1) <_ C <-> -. C < (C + 1))
5856, 57sylib 198 . . . . . . . . . . 11 |- ((-uB =/= 0 /\ 0 = A) -> -. C < (C + 1))
5958ex 373 . . . . . . . . . 10 |- (-uB =/= 0 -> (0 = A -> -. C < (C + 1)))
607, 59sylbi 199 . . . . . . . . 9 |- (-. B = 0 -> (0 = A -> -. C < (C + 1)))
612, 60mt2i 110 . . . . . . . 8 |- (-. B = 0 -> -. 0 = A)
6261a3i 74 . . . . . . 7 |- (0 = A -> B = 0)
6362opreq1d 3960 . . . . . 6 |- (0 = A -> (B x. B) = (0 x. B))
645mul02 5404 . . . . . 6 |- (0 x. B) = 0
6563, 64syl6eq 1515 . . . . 5 |- (0 = A -> (B x. B) = 0)
665sqval 6544 . . . . 5 |- (B^2) = (B x. B)
6765, 66syl5eq 1511 . . . 4 |- (0 = A -> (B^2) = 0)
68 opreq1 3953 . . . . . . 7 |- (0 = A -> (0 x. C) = (A x. C))
691recn 5286 . . . . . . . 8 |- C e. CC
7069mul02 5404 . . . . . . 7 |- (0 x. C) = 0
7168, 70syl5reqr 1514 . . . . . 6 |- (0 = A -> (A x. C) = 0)
7271opreq2d 3961 . . . . 5 |- (0 = A -> (4 x. (A x. C)) = (4 x. 0))
73 4re 5929 . . . . . . 7 |- 4 e. RR
7473recn 5286 . . . . . 6 |- 4 e. CC
7574mul01 5403 . . . . 5 |- (4 x. 0) = 0
7672, 75syl6eq 1515 . . . 4 |- (0 = A -> (4 x. (A x. C)) = 0)
7767, 76opreq12d 3963 . . 3 |- (0 = A -> ((B^2) - (4 x. (A x. C))) = (0 - 0))
78 0cn 5300 . . . 4 |- 0 e. CC
7978subid 5363 . . 3 |- (0 - 0) = 0
8077, 79syl6eq 1515 . 2 |- (0 = A -> ((B^2) - (4 x. (A x. C))) = 0)
814resqcl 6554 . . . 4 |- (B^2) e. RR
82 discrlem.1 . . . . . 6 |- A e. RR
8382, 1remulcl 5307 . . . . 5 |- (A x. C) e. RR
8473, 83remulcl 5307 . . . 4 |- (4 x. (A x. C)) e. RR
8581, 84resubcl 5411 . . 3 |- ((B^2) - (4 x. (A x. C))) e. RR
8685, 35eqle 5555 . 2 |- (((B^2) - (4 x. (A x. C))) = 0 -> ((B^2) - (4 x. (A x. C))) <_ 0)
8780, 86syl 10 1 |- (0 = A -> ((B^2) - (4 x. (A x. C))) <_ 0)
Colors of variables: wff set class
Syntax hints:  -. wn 2   -> wi 3   <-> wb 146   /\ wa 223   = wceq 953   e. wcel 955   =/= wne 1577   class class class wbr 2609  (class class class)co 3948  CCcc 5204  RRcr 5205  0cc0 5206  1c1 5207   + caddc 5209   x. cmul 5211   - cmin 5264  -ucneg 5265   / cdiv 5266   <_ cle 5267   < clt 5458  2c2 5908  4c4 5910  ^cexp 6500
This theorem is referenced by:  discrlem 6589
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-nul 2700  ax-pow 2732  ax-pr 2769  ax-un 2857  ax-inf2 4597
This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225  df-3or 774  df-3an 775  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-nel 1580  df-ral 1641  df-rex 1642  df-reu 1643  df-rab 1644  df-v 1803  df-sbc 1932  df-csb 1992  df-dif 2039  df-un 2040  df-in 2041  df-ss 2043  df-pss 2045  df-nul 2271  df-if 2352  df-pw 2392  df-sn 2402  df-pr 2403  df-tp 2405  df-op 2406  df-uni 2494  df-int 2524  df-iun 2558  df-br 2610  df-opab 2657  df-tr 2671  df-eprel 2821  df-id 2824  df-po 2831  df-so 2841  df-fr 2907  df-we 2924