HomeHome Hilbert Space Explorer < Previous   Next >
Related theorems
GIF version

Theorem normpar2 5100
Description: Corollary of parallelogram law for norms. Part of Lemma 3.6 of [Beran] p. 100.
Hypotheses
Ref Expression
normpar2.1 A ∈ ℋ
normpar2.2 B ∈ ℋ
normpar2.3 C ∈ ℋ
Assertion
Ref Expression
normpar2 ((norm ‘(Av B))↑2) = (((2 · ((norm ‘(Av C))↑2)) + (2 · ((norm ‘(Bv C))↑2))) − ((norm ‘((A +v B) −v (2 ·s C)))↑2))

Proof of Theorem normpar2
StepHypRef Expression
1 4re 4473 . . . . . . 7 4 ∈ ℝ
21recn 4098 . . . . . 6 4 ∈ ℂ
3 normpar2.1 . . . . . . . . . 10 A ∈ ℋ
4 normpar2.3 . . . . . . . . . 10 C ∈ ℋ
53, 4hvsubcl 5002 . . . . . . . . 9 (Av C) ∈ ℋ
65normcl 5081 . . . . . . . 8 (norm ‘(Av C)) ∈ ℝ
76sqrecl 4699 . . . . . . 7 ((norm ‘(Av C))↑2) ∈ ℝ
87recn 4098 . . . . . 6 ((norm ‘(Av C))↑2) ∈ ℂ
92, 8mulcl 4105 . . . . 5 (4 · ((norm ‘(Av C))↑2)) ∈ ℂ
10 normpar2.2 . . . . . . . . . 10 B ∈ ℋ
1110, 4hvsubcl 5002 . . . . . . . . 9 (Bv C) ∈ ℋ
1211normcl 5081 . . . . . . . 8 (norm ‘(Bv C)) ∈ ℝ
1312sqrecl 4699 . . . . . . 7 ((norm ‘(Bv C))↑2) ∈ ℝ
1413recn 4098 . . . . . 6 ((norm ‘(Bv C))↑2) ∈ ℂ
152, 14mulcl 4105 . . . . 5 (4 · ((norm ‘(Bv C))↑2)) ∈ ℂ
16 2cn 4471 . . . . 5 2 ∈ ℂ
17 2re 4470 . . . . . 6 2 ∈ ℝ
18 2pos 4479 . . . . . 6 0 < 2
1917, 18gt0ne0i 4345 . . . . 5 2 ≠ 0
209, 15, 16, 19divdistr 4243 . . . 4 (((4 · ((norm ‘(Av C))↑2)) + (4 · ((norm ‘(Bv C))↑2))) / 2) = (((4 · ((norm ‘(Av C))↑2)) / 2) + ((4 · ((norm ‘(Bv C))↑2)) / 2))
219, 15addcom 4106 . . . . . . . 8 ((4 · ((norm ‘(Av C))↑2)) + (4 · ((norm ‘(Bv C))↑2))) = ((4 · ((norm ‘(Bv C))↑2)) + (4 · ((norm ‘(Av C))↑2)))
223, 10hvaddcl 4999 . . . . . . . . . . . . . . . . 17 (A +v B) ∈ ℋ
2316, 4hvmulcl 4990 . . . . . . . . . . . . . . . . 17 (2 ·s C) ∈ ℋ
2422, 23hvsubcl 5002 . . . . . . . . . . . . . . . 16 ((A +v B) −v (2 ·s C)) ∈ ℋ
253, 10hvsubcl 5002 . . . . . . . . . . . . . . . 16 (Av B) ∈ ℋ
2624, 25hvsubval 5001 . . . . . . . . . . . . . . 15 (((A +v B) −v (2 ·s C)) −v (Av B)) = (((A +v B) −v (2 ·s C)) +v (-1 ·s (Av B)))
2722, 23hvsubval 5001 . . . . . . . . . . . . . . . 16 ((A +v B) −v (2 ·s C)) = ((A +v B) +v (-1 ·s (2 ·s C)))
2827opreq1i 3009 . . . . . . . . . . . . . . 15 (((A +v B) −v (2 ·s C)) +v (-1 ·s (Av B))) = (((A +v B) +v (-1 ·s (2 ·s C))) +v (-1 ·s (Av B)))
293, 10hvcom 5000 . . . . . . . . . . . . . . . . . . 19 (A +v B) = (B +v A)
303, 10hvnegdi 5034 . . . . . . . . . . . . . . . . . . 19 (-1 ·s (Av B)) = (Bv A)
3129, 30opreq12i 3011 . . . . . . . . . . . . . . . . . 18 ((A +v B) +v (-1 ·s (Av B))) = ((B +v A) +v (Bv A))
3210, 3hvsubcan2 5036 . . . . . . . . . . . . . . . . . 18 ((B +v A) +v (Bv A)) = (2 ·s B)
3331, 32eqtr 1119 . . . . . . . . . . . . . . . . 17 ((A +v B) +v (-1 ·s (Av B))) = (2 ·s B)
3433opreq1i 3009 . . . . . . . . . . . . . . . 16 (((A +v B) +v (-1 ·s (Av B))) +v (-1 ·s (2 ·s C))) = ((2 ·s B) +v (-1 ·s (2 ·s C)))
35 1cn 4101 . . . . . . . . . . . . . . . . . . 19 1 ∈ ℂ
3635negcl 4142 . . . . . . . . . . . . . . . . . 18 -1 ∈ ℂ
3736, 23hvmulcl 4990 . . . . . . . . . . . . . . . . 17 (-1 ·s (2 ·s C)) ∈ ℋ
3836, 25hvmulcl 4990 . . . . . . . . . . . . . . . . 17 (-1 ·s (Av B)) ∈ ℋ
3922, 37, 38hvadd23 5026 . . . . . . . . . . . . . . . 16 (((A +v B) +v (-1 ·s (2 ·s C))) +v (-1 ·s (Av B))) = (((A +v B) +v (-1 ·s (Av B))) +v (-1 ·s (2 ·s C)))
4016, 10hvmulcl 4990 . . . . . . . . . . . . . . . . 17 (2 ·s B) ∈ ℋ
4140, 23hvsubval 5001 . . . . . . . . . . . . . . . 16 ((2 ·s B) −v (2 ·s C)) = ((2 ·s B) +v (-1 ·s (2 ·s C)))
4234, 39, 413eqtr4 1126 . . . . . . . . . . . . . . 15 (((A +v B) +v (-1 ·s (2 ·s C))) +v (-1 ·s (Av B))) = ((2 ·s B) −v (2 ·s C))
4326, 28, 423eqtr 1123 . . . . . . . . . . . . . 14 (((A +v B) −v (2 ·s C)) −v (Av B)) = ((2 ·s B) −v (2 ·s C))
4416, 10, 4hvsubdistr1 5024 . . . . . . . . . . . . . 14 (2 ·s (Bv C)) = ((2 ·s B) −v (2 ·s C))
4543, 44eqtr4 1122 . . . . . . . . . . . . 13 (((A +v B) −v (2 ·s C)) −v (Av B)) = (2 ·s (Bv C))
4645fveq2i 2835 . . . . . . . . . . . 12 (norm ‘(((A +v B) −v (2 ·s C)) −v (Av B))) = (norm ‘(2 ·s (Bv C)))
4716, 11norm-iii 5087 . . . . . . . . . . . 12 (norm ‘(2 ·s (Bv C))) = ((abs ‘2) · (norm ‘(Bv C)))
48 ax0re 4063 . . . . . . . . . . . . . . 15 0 ∈ ℝ
4948, 17, 18ltlei 4303 . . . . . . . . . . . . . 14 0 ≤ 2
5017absid 4850 . . . . . . . . . . . . . 14 (0 ≤ 2 → (abs ‘2) = 2)
5149, 50ax-mp 6 . . . . . . . . . . . . 13 (abs ‘2) = 2
5251opreq1i 3009 . . . . . . . . . . . 12 ((abs ‘2) · (norm ‘(Bv C))) = (2 · (norm ‘(Bv C)))
5346, 47, 523eqtr 1123 . . . . . . . . . . 11 (norm ‘(((A +v B) −v (2 ·s C)) −v (Av B))) = (2 · (norm ‘(Bv C)))
5453opreq1i 3009 . . . . . . . . . 10 ((norm ‘(((A +v B) −v (2 ·s C)) −v (Av B)))↑2) = ((2 · (norm ‘(Bv C)))↑2)
5512recn 4098 . . . . . . . . . . 11 (norm ‘(Bv C)) ∈ ℂ
5616, 55sqmul 4688 . . . . . . . . . 10 ((2 · (norm ‘(Bv C)))↑2) = ((2↑2) · ((norm ‘(Bv C))↑2))
57 sq2 4710 . . . . . . . . . . 11 (2↑2) = 4
5857opreq1i 3009 . . . . . . . . . 10 ((2↑2) · ((norm ‘(Bv C))↑2)) = (4 · ((norm ‘(Bv C))↑2))
5954, 56, 583eqtr 1123 . . . . . . . . 9 ((norm ‘(((A +v B) −v (2 ·s C)) −v (Av B)))↑2) = (4 · ((norm ‘(Bv C))↑2))
6027opreq1i 3009 . . . . . . . . . . . . . . 15 (((A +v B) −v (2 ·s C)) +v (Av B)) = (((A +v B) +v (-1 ·s (2 ·s C))) +v (Av B))
6122, 37, 25hvadd23 5026 . . . . . . . . . . . . . . 15 (((A +v B) +v (-1 ·s (2 ·s C))) +v (Av B)) = (((A +v B) +v (Av B)) +v (-1 ·s (2 ·s C)))
623, 10hvsubcan2 5036 . . . . . . . . . . . . . . . . 17 ((A +v B) +v (Av B)) = (2 ·s A)
6362opreq1i 3009 . . . . . . . . . . . . . . . 16 (((A +v B) +v (Av B)) +v (-1 ·s (2 ·s C))) = ((2 ·s A) +v (-1 ·s (2 ·s C)))
6416, 3hvmulcl 4990 . . . . . . . . . . . . . . . . 17 (2 ·s A) ∈ ℋ
6564, 23hvsubval 5001 . . . . . . . . . . . . . . . 16 ((2 ·s A) −v (2 ·s C)) = ((2 ·s A) +v (-1 ·s (2 ·s C)))
6663, 65eqtr4 1122 . . . . . . . . . . . . . . 15 (((A +v B) +v (Av B)) +v (-1 ·s (2 ·s C))) = ((2 ·s A) −v (2 ·s C))
6760, 61, 663eqtr 1123 . . . . . . . . . . . . . 14 (((A +v B) −v (2 ·s C)) +v (Av B)) = ((2 ·s A) −v (2 ·s C))
6816, 3, 4hvsubdistr1 5024 . . . . . . . . . . . . . 14 (2 ·s (Av C)) = ((2 ·s A) −v (2 ·s C))
6967, 68eqtr4 1122 . . . . . . . . . . . . 13 (((A +v B) −v (2 ·s C)) +v (Av B)) = (2 ·s (Av C))
7069fveq2i 2835 . . . . . . . . . . . 12 (norm ‘(((A +v B) −v (2 ·s C)) +v (Av B))) = (norm ‘(2 ·s (Av C)))
7116, 5norm-iii 5087 . . . . . . . . . . . 12 (norm ‘(2 ·s (Av C))) = ((abs ‘2) · (norm ‘(Av C)))
7251opreq1i 3009 . . . . . . . . . . . 12 ((abs ‘2) · (norm ‘(Av C))) = (2 · (norm ‘(Av C)))
7370, 71, 723eqtr 1123 . . . . . . . . . . 11 (norm ‘(((A +v B) −v (2 ·s C)) +v (Av B))) = (2 · (norm ‘(Av C)))
7473opreq1i 3009 . . . . . . . . . 10 ((norm ‘(((A +v B) −v (2 ·s C)) +v (Av B)))↑2) = ((2 · (norm ‘(Av C)))↑2)
756recn 4098 . . . . . . . . . . 11 (norm ‘(Av C)) ∈ ℂ
7616, 75sqmul 4688 . . . . . . . . . 10 ((2 · (norm ‘(Av C)))↑2) = ((2↑2) · ((norm ‘(Av C))↑2))
7757opreq1i 3009 . . . . . . . . . 10 ((2↑2) · ((norm ‘(Av C))↑2)) = (4 · ((norm ‘(Av C))↑2))
7874, 76, 773eqtr 1123 . . . . . . . . 9 ((norm ‘(((A +v B) −v (2 ·s C)) +v (Av B)))↑2) = (4 · ((norm ‘(Av C))↑2))
7959, 78opreq12i 3011 . . . . . . . 8 (((norm ‘(((A +v B) −v (2 ·s C)) −v (Av B)))↑2) + ((norm ‘(((A +v B) −v (2 ·s C)) +v (Av B)))↑2)) = ((4 · ((norm ‘(Bv C))↑2)) + (4 · ((norm ‘(Av C))↑2)))
8021, 79eqtr4 1122 . . . . . . 7 ((4 · ((norm ‘(Av C))↑2)) + (4 · ((norm ‘(Bv C))↑2))) = (((norm ‘(((A +v B) −v (2 ·s C)) −v (Av B)))↑2) + ((norm ‘(((A +v B) −v (2 ·s C)) +v (Av B)))↑2))
8124, 25normpar 5099 . . . . . . 7 (((norm ‘(((A +v B) −v (2 ·s C)) −v (Av B)))↑2) + ((norm ‘(((A +v B) −v (2 ·s C)) +v (Av B)))↑2)) = ((2 · ((norm ‘((A +v B) −v (2 ·s C)))↑2)) + (2 · ((norm ‘(Av B))↑2)))
8280, 81eqtr 1119 . . . . . 6 ((4 · ((norm ‘(Av C))↑2)) + (4 · ((norm ‘(Bv C))↑2))) = ((2 · ((norm ‘((A +v B) −v (2 ·s C)))↑2)) + (2 · ((norm ‘(Av B))↑2)))
8382opreq1i 3009 . . . . 5 (((4 · ((norm ‘(Av C))↑2)) + (4 · ((norm ‘(Bv C))↑2))) / 2) = (((2 · ((norm ‘((A +v B) −v (2 ·s C)))↑2)) + (2 · ((norm ‘(Av B))↑2))) / 2)
8424normcl 5081 . . . . . . . . 9 (norm ‘((A +v B) −v (2 ·s C))) ∈ ℝ
8584sqrecl 4699 . . . . . . . 8 ((norm ‘((A +v B) −v (2 ·s C)))↑2) ∈ ℝ
8685recn 4098 . . . . . . 7 ((norm ‘((A +v B) −v (2 ·s C)))↑2) ∈ ℂ
8716, 86mulcl 4105 . . . . . 6 (2 · ((norm ‘((A +v B) −v (2 ·s C)))↑2)) ∈ ℂ
8825normcl 5081 . . . . . . . . 9 (norm ‘(Av B)) ∈ ℝ
8988sqrecl 4699 . . . . . . . 8 ((norm ‘(Av B))↑2) ∈ ℝ
9089recn 4098 . . . . . . 7 ((norm ‘(Av B))↑2) ∈ ℂ
9116, 90mulcl 4105 . . . . . 6 (2 · ((norm ‘(Av B))↑2)) ∈ ℂ
9287, 91, 16, 19divdistr 4243 . . . . 5 (((2 · ((norm ‘((A +v B) −v (2 ·s C)))↑2)) + (2 · ((norm ‘(Av B))↑2))) / 2) = (((2 · ((norm ‘((A +v B) −v (2 ·s C)))↑2)) / 2) + ((2 · ((norm ‘(Av B))↑2)) / 2))
9316, 86, 19divcan3 4247 . . . . . 6 ((2 · ((norm ‘((A +v B) −v (2 ·s C)))↑2)) / 2) = ((norm ‘((A +v B) −v (2 ·s C)))↑2)
9416, 90, 19divcan3 4247 . . . . . 6 ((2 · ((norm ‘(Av B))↑2)) / 2) = ((norm ‘(Av B))↑2)
9593, 94opreq12i 3011 . . . . 5 (((2 · ((norm ‘((A +v B) −v (2 ·s C)))↑2)) / 2) + ((2 · ((norm ‘(Av B))↑2)) / 2)) = (((norm ‘((A +v B) −v (2 ·s C)))↑2) + ((norm ‘(Av B))↑2))
9683, 92, 953eqtr 1123 . . . 4 (((4 · ((norm ‘(Av C))↑2)) + (4 · ((norm ‘(Bv C))↑2))) / 2) = (((norm ‘((A +v B) −v (2 ·s C)))↑2) + ((norm ‘(Av B))↑2))
972, 8, 16, 19div23 4244 . . . . . 6 ((4 · ((norm ‘(Av C))↑2)) / 2) = ((4 / 2) · ((norm ‘(Av C))↑2))
98 4d2e2 4507 . . . . . . 7 (4 / 2) = 2
9998opreq1i 3009 . . . . . 6 ((4 / 2) · ((norm ‘(Av C))↑2)) = (2 · ((norm ‘(Av C))↑2))
10097, 99eqtr 1119 . . . . 5 ((4 · ((norm ‘(Av C))↑2)) / 2) = (2 · ((norm ‘(Av C))↑2))
1012, 14, 16, 19div23 4244 . . . . . 6 ((4 · ((norm ‘(Bv C))↑2)) / 2) = ((4 / 2) · ((norm ‘(Bv C))↑2))
10298opreq1i 3009 . . . . . 6 ((4 / 2) · ((norm ‘(Bv C))↑2)) = (2 · ((norm ‘(Bv C))↑2))
103101, 102eqtr 1119 . . . . 5 ((4 · ((norm ‘(Bv C))↑2)) / 2) = (2 · ((norm ‘(Bv C))↑2))
104100, 103opreq12i 3011 . . . 4 (((4 · ((norm ‘(Av C))↑2)) / 2) + ((4 · ((norm ‘(Bv C))↑2)) / 2)) = ((2 · ((norm ‘(Av C))↑2)) + (2 · ((norm ‘(Bv C))↑2)))
10520, 96, 1043eqtr3 1124 . . 3 (((norm ‘((A +v B) −v (2 ·s C)))↑2) + ((norm ‘(Av B))↑2)) = ((2 · ((norm ‘(Av C))↑2)) + (2 · ((norm ‘(Bv C))↑2)))
10617, 7remulcl 4119 . . . . . 6 (2 · ((norm ‘(Av C))↑2)) ∈ ℝ
10717, 13remulcl 4119 . . . . . 6 (2 · ((norm ‘(Bv C))↑2)) ∈ ℝ
108106, 107readdcl 4118 . . . . 5 ((2 · ((norm ‘(Av C))↑2)) + (2 · ((norm ‘(Bv C))↑2))) ∈ ℝ
109108recn 4098 . . . 4 ((2 · ((norm ‘(Av C))↑2)) + (2 · ((norm ‘(Bv C))↑2))) ∈ ℂ
110109, 86, 90subadd 4143 . . 3 ((((2 · ((norm ‘(Av C))↑2)) + (2 · ((norm ‘(Bv C))↑2))) − ((norm ‘((A +v B) −v (2 ·s C)))↑2)) = ((norm ‘(Av B))↑2) ↔ (((norm ‘((A +v B) −v (2 ·s C)))↑2) + ((norm ‘(Av B))↑2)) = ((2 · ((norm ‘(Av C))↑2)) + (2 · ((norm ‘(Bv C))↑2))))
111105, 110mpbir 165 . 2 (((2 · ((norm ‘(Av C))↑2)) + (2 · ((norm ‘(Bv C))↑2))) − ((norm ‘((A +v B) −v (2 ·s C)))↑2)) = ((norm ‘(Av B))↑2)
112111cleqcomi 1105 1 ((norm ‘(Av B))↑2) = (((2 · ((norm ‘(Av C))↑2)) + (2 · ((norm ‘(Bv C))↑2))) − ((norm ‘((A +v B) −v (2 ·s C)))↑2))
Colors of variables: wff set class
Syntax hints:   = wceq 1091   ∈ wcel 1092   class class class wbr 2054   ‘cfv 2422  (class class class)co 3001  0cc0 4028  1c1 4029   + caddc 4031   · cmulc 4032   − cmin 4089  -cneg 4090   / cdiv 4091   ≤ cle 4092  2c2 4454  4c4 4456  ↑cexp 4675  abscabs 4789   ℋ chil 4958   +v cva 4959   ·s csm 4960   −v cmv 4962  normcno 4964
This theorem is referenced by:  projlem5 5197
This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6  ax-4 673  ax-5 674  ax-6 675  ax-7 676  ax-gen 677  ax-8 798  ax-9 799  ax-10 800  ax-11 801  ax-12 802  ax-13 804  ax-14 805  ax-16 922  ax-17 925  ax-ext 1074  ax-rep 1075  ax-un 1076  ax-pow 1077  ax-reg 1078  ax-inf 1079  ax-hvaddcl 4984  ax-hvcom 4985  ax-hvass 4986  ax-hvzercl 4987  ax-hvaddid 4988  ax-hvmulcl 4989  ax-hvmulid 4991  ax-hvmulass 4992  ax-hvdistr1 4993  ax-hvdistr2 4994  ax-hvmulzer 4995  ax-hicl 5043  ax-his1 5045  ax-his2 5046  ax-his3 5047  ax-his4 5048
This theorem depends on definitions:  df-bi 128  df-or 197  df-an 198  df-3or 582  df-3an 583  df-ex 679  df-sb 853  df-eu 1009  df-mo 1010  df-clab 1093  df-cleq 1097  df-clel 1099  df-ne 1192  df-ral 1205  df-rex 1206  df-reu 1207  df-rab 1208  df-v 1349  df-sbc 1441  df-dif 1489  df-un 1490  df-in 1491  df-ss 1492  df-pss 1494  df-nul 1708  df-if 1777  df-pw 1799  df-sn 1811  df-pr 1812  df-tp 1814  df-op 1815  df-uni 1920  df-int 1966  df-iun 1996  df-tr 2042  df-br 2063  df-opab 2098  df-eprel 2122  df-id 2125  df-po 2128  df-so 2138  df-sup 2154  df-fr 2169  df-we 2186  df-ord 2202  df-on 2203  df-lim 2204  df-suc 2205  df-om 2373  df-xp 2424  df-rel 2425  df-cnv 2426  df-co 2427  df-dm 2428  df-rn 2429  df-res 2430  df-ima 2431  df-fun 2432  df-fn 2433  df-f 2434  df-f1 2435  df-fo 2436  df-f1o 2437  df-fv 2438  df-rdg 2970  df-opr 3003  df-oprab 3004  df-1st 3087  df-2nd 3088  df-1o 3104  df-oadd 3106  df-omul 3107  df-er 3200  df-ec 3202  df-qs 3205  df-ni 3794  df-pli 3795  df-mi 3796  df-lti 3797  df-plpq 3829  df-mpq 3830  df-enq 3831  df-nq 3832  df-plq 3833  df-mq 3834  df-rq 3835  df-ltq 3836  df-1q 3837  df-np 3880  df-1p 3881  df-plp 3882  df-mp 3883  df-ltp 3884  df-plpr 3958  df-mpr 3959  df-enr 3960  df-nr 3961  df-plr 3962  df-mr 3963  df-ltr 3964  df-0r 3965  df-1r 3966  df-m1r 3967  df-c 4034  df-0 4035  df-1 4036  df-i 4037  df-r 4038  df-plus 4039  df-mul 4040  df-lt 4041  df-sub 4133  df-neg 4135  df-div 4216  df-le 4277  df-n 4423  df-2 4462  df-3 4463  df-4 4464  df-n0 4535  df-z 4564  df-seq 4661  df-exp 4676  df-sqr 4728  df-re 4790  df-im 4791  df-cj 4792  df-abs 4793  df-hvsub 4996  df-hnorm 5074
metamath.org