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Unicode version

Theorem trirni 15833
Description: Triangle inequality in R^n.
Hypotheses
Ref Expression
trirni.1 |- N e. NN
trirni.2 |- X:(1...N)-->RR
trirni.3 |- Y:(1...N)-->RR
Assertion
Ref Expression
trirni |- (sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2)) <_ ((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr` sum_k e. (1...N)((Y` k)^2)))
Distinct variable groups:   k,N   k,X   k,Y

Proof of Theorem trirni
StepHypRef Expression
1 trirni.1 . . . . . . . . . . 11 |- N e. NN
2 elnnuz 7609 . . . . . . . . . . 11 |- (N e. NN <-> N e. (ZZ>=` 1))
31, 2mpbi 206 . . . . . . . . . 10 |- N e. (ZZ>=` 1)
4 trirni.2 . . . . . . . . . . . . 13 |- X:(1...N)-->RR
54ffvelrni 4788 . . . . . . . . . . . 12 |- (k e. (1...N) -> (X` k) e. RR)
6 trirni.3 . . . . . . . . . . . . 13 |- Y:(1...N)-->RR
76ffvelrni 4788 . . . . . . . . . . . 12 |- (k e. (1...N) -> (Y` k) e. RR)
8 remulcl 6457 . . . . . . . . . . . 12 |- (((X` k) e. RR /\ (Y` k) e. RR) -> ((X` k) x. (Y` k)) e. RR)
95, 7, 8syl11anc 524 . . . . . . . . . . 11 |- (k e. (1...N) -> ((X` k) x. (Y` k)) e. RR)
109rgen 2159 . . . . . . . . . 10 |- A.k e. (1...N)((X` k) x. (Y` k)) e. RR
11 fsumrecl 8277 . . . . . . . . . 10 |- ((N e. (ZZ>=` 1) /\ A.k e. (1...N)((X` k) x. (Y` k)) e. RR) -> sum_k e. (1...N)((X` k) x. (Y` k)) e. RR)
123, 10, 11mp2an 761 . . . . . . . . 9 |- sum_k e. (1...N)((X` k) x. (Y` k)) e. RR
1312leabsi 8124 . . . . . . . 8 |- sum_k e. (1...N)((X` k) x. (Y` k)) <_ (abs` sum_k e. (1...N)((X` k) x. (Y` k)))
141, 4, 6csbrni 15832 . . . . . . . . . 10 |- (sum_k e. (1...N)((X` k) x. (Y` k))^2) <_ (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))
15 absresq 8118 . . . . . . . . . . 11 |- (sum_k e. (1...N)((X` k) x. (Y` k)) e. RR -> ((abs` sum_k e. (1...N)((X` k) x. (Y` k)))^2) = (sum_k e. (1...N)((X` k) x. (Y` k))^2))
1612, 15ax-mp 7 . . . . . . . . . 10 |- ((abs` sum_k e. (1...N)((X` k) x. (Y` k)))^2) = (sum_k e. (1...N)((X` k) x. (Y` k))^2)
17 reexpcl 7823 . . . . . . . . . . . . . . . 16 |- (((X` k) e. RR /\ 2 e. NN0) -> ((X` k)^2) e. RR)
18 2nn0 7324 . . . . . . . . . . . . . . . 16 |- 2 e. NN0
1917, 5, 18sylancl 525 . . . . . . . . . . . . . . 15 |- (k e. (1...N) -> ((X` k)^2) e. RR)
20 sqge0 7878 . . . . . . . . . . . . . . . 16 |- ((X` k) e. RR -> 0 <_ ((X` k)^2))
215, 20syl 12 . . . . . . . . . . . . . . 15 |- (k e. (1...N) -> 0 <_ ((X` k)^2))
2219, 21jca 310 . . . . . . . . . . . . . 14 |- (k e. (1...N) -> (((X` k)^2) e. RR /\ 0 <_ ((X` k)^2)))
2322rgen 2159 . . . . . . . . . . . . 13 |- A.k e. (1...N)(((X` k)^2) e. RR /\ 0 <_ ((X` k)^2))
24 fsumcmp0 8301 . . . . . . . . . . . . 13 |- ((N e. (ZZ>=` 1) /\ A.k e. (1...N)(((X` k)^2) e. RR /\ 0 <_ ((X` k)^2))) -> 0 <_ sum_k e. (1...N)((X` k)^2))
253, 23, 24mp2an 761 . . . . . . . . . . . 12 |- 0 <_ sum_k e. (1...N)((X` k)^2)
26 reexpcl 7823 . . . . . . . . . . . . . . . 16 |- (((Y` k) e. RR /\ 2 e. NN0) -> ((Y` k)^2) e. RR)
2726, 7, 18sylancl 525 . . . . . . . . . . . . . . 15 |- (k e. (1...N) -> ((Y` k)^2) e. RR)
28 sqge0 7878 . . . . . . . . . . . . . . . 16 |- ((Y` k) e. RR -> 0 <_ ((Y` k)^2))
297, 28syl 12 . . . . . . . . . . . . . . 15 |- (k e. (1...N) -> 0 <_ ((Y` k)^2))
3027, 29jca 310 . . . . . . . . . . . . . 14 |- (k e. (1...N) -> (((Y` k)^2) e. RR /\ 0 <_ ((Y` k)^2)))
3130rgen 2159 . . . . . . . . . . . . 13 |- A.k e. (1...N)(((Y` k)^2) e. RR /\ 0 <_ ((Y` k)^2))
32 fsumcmp0 8301 . . . . . . . . . . . . 13 |- ((N e. (ZZ>=` 1) /\ A.k e. (1...N)(((Y` k)^2) e. RR /\ 0 <_ ((Y` k)^2))) -> 0 <_ sum_k e. (1...N)((Y` k)^2))
333, 31, 32mp2an 761 . . . . . . . . . . . 12 |- 0 <_ sum_k e. (1...N)((Y` k)^2)
3419rgen 2159 . . . . . . . . . . . . . 14 |- A.k e. (1...N)((X` k)^2) e. RR
35 fsumrecl 8277 . . . . . . . . . . . . . 14 |- ((N e. (ZZ>=` 1) /\ A.k e. (1...N)((X` k)^2) e. RR) -> sum_k e. (1...N)((X` k)^2) e. RR)
363, 34, 35mp2an 761 . . . . . . . . . . . . 13 |- sum_k e. (1...N)((X` k)^2) e. RR
3727rgen 2159 . . . . . . . . . . . . . 14 |- A.k e. (1...N)((Y` k)^2) e. RR
38 fsumrecl 8277 . . . . . . . . . . . . . 14 |- ((N e. (ZZ>=` 1) /\ A.k e. (1...N)((Y` k)^2) e. RR) -> sum_k e. (1...N)((Y` k)^2) e. RR)
393, 37, 38mp2an 761 . . . . . . . . . . . . 13 |- sum_k e. (1...N)((Y` k)^2) e. RR
4036, 39mulge0i 6787 . . . . . . . . . . . 12 |- ((0 <_ sum_k e. (1...N)((X` k)^2) /\ 0 <_ sum_k e. (1...N)((Y` k)^2)) -> 0 <_ (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))
4125, 33, 40mp2an 761 . . . . . . . . . . 11 |- 0 <_ (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))
4236, 39remulcli 6488 . . . . . . . . . . . 12 |- (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)) e. RR
4342sqsqri 7971 . . . . . . . . . . 11 |- (0 <_ (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)) -> ((sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))^2) = (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))
4441, 43ax-mp 7 . . . . . . . . . 10 |- ((sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))^2) = (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))
4514, 16, 443brtr4i 3365 . . . . . . . . 9 |- ((abs` sum_k e. (1...N)((X` k) x. (Y` k)))^2) <_ ((sqr`
(sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))^2)
4612recni 6467 . . . . . . . . . . 11 |- sum_k e. (1...N)((X` k) x. (Y` k)) e. CC
4746absge0i 8091 . . . . . . . . . 10 |- 0 <_ (abs` sum_k e. (1...N)((X` k) x. (Y` k)))
4842sqrge0i 7952 . . . . . . . . . . 11 |- (0 <_ (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)) -> 0 <_ (sqr`
(sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))))
4941, 48ax-mp 7 . . . . . . . . . 10 |- 0 <_ (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))
5046abscli 8090 . . . . . . . . . . 11 |- (abs` sum_k e. (1...N)((X` k) x. (Y` k))) e. RR
5142sqrcli 7950 . . . . . . . . . . . 12 |- (0 <_ (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)) -> (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))) e. RR)
5241, 51ax-mp 7 . . . . . . . . . . 11 |- (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))) e. RR
5350, 52le2sqi 7870 . . . . . . . . . 10 |- ((0 <_ (abs` sum_k e. (1...N)((X` k) x. (Y` k))) /\ 0 <_ (sqr`
(sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))) -> ((abs`
sum_k e. (1...N)((X` k) x. (Y` k))) <_ (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))) <-> ((abs`
sum_k e. (1...N)((X` k) x. (Y` k)))^2) <_ ((sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))^2)))
5447, 49, 53mp2an 761 . . . . . . . . 9 |- ((abs` sum_k e. (1...N)((X` k) x. (Y` k))) <_ (sqr`
(sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))) <-> ((abs` sum_k e. (1...N)((X` k) x. (Y` k)))^2) <_ ((sqr`
(sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))^2))
5545, 54mpbir 207 . . . . . . . 8 |- (abs` sum_k e. (1...N)((X` k) x. (Y` k))) <_ (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))
5612, 50, 52letri 6763 . . . . . . . 8 |- ((sum_k e. (1...N)((X` k) x. (Y` k)) <_ (abs` sum_k e. (1...N)((X` k) x. (Y` k))) /\ (abs` sum_k e. (1...N)((X` k) x. (Y` k))) <_ (sqr`
(sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))) -> sum_k e. (1...N)((X` k) x. (Y` k)) <_ (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))))
5713, 55, 56mp2an 761 . . . . . . 7 |- sum_k e. (1...N)((X` k) x. (Y` k)) <_ (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))
58 2pos 7173 . . . . . . . 8 |- 0 < 2
59 2re 7163 . . . . . . . . 9 |- 2 e. RR
6012, 52, 59lemul2i 7018 . . . . . . . 8 |- (0 < 2 -> (sum_k e. (1...N)((X` k) x. (Y` k)) <_ (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))) <-> (2 x. sum_k e. (1...N)((X` k) x. (Y` k))) <_ (2 x. (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))))))
6158, 60ax-mp 7 . . . . . . 7 |- (sum_k e. (1...N)((X` k) x. (Y` k)) <_ (sqr`
(sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))) <-> (2 x. sum_k e. (1...N)((X` k) x. (Y` k))) <_ (2 x. (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))))
6257, 61mpbi 206 . . . . . 6 |- (2 x. sum_k e. (1...N)((X` k) x. (Y` k))) <_ (2 x. (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))))
63 2cn 7164 . . . . . . 7 |- 2 e. CC
645recnd 6468 . . . . . . . . 9 |- (k e. (1...N) -> (X` k) e. CC)
657recnd 6468 . . . . . . . . 9 |- (k e. (1...N) -> (Y` k) e. CC)
66 mulcl 6456 . . . . . . . . 9 |- (((X` k) e. CC /\ (Y` k) e. CC) -> ((X` k) x. (Y` k)) e. CC)
6764, 65, 66syl11anc 524 . . . . . . . 8 |- (k e. (1...N) -> ((X` k) x. (Y` k)) e. CC)
6867rgen 2159 . . . . . . 7 |- A.k e. (1...N)((X` k) x. (Y` k)) e. CC
69 fsummulc1 8293 . . . . . . 7 |- ((N e. (ZZ>=` 1) /\ 2 e. CC /\ A.k e. (1...N)((X` k) x. (Y` k)) e. CC) -> (2 x. sum_k e. (1...N)((X` k) x. (Y` k))) = sum_k e. (1...N)(2 x. ((X` k) x. (Y` k))))
703, 63, 68, 69mp3an 1191 . . . . . 6 |- (2 x. sum_k e. (1...N)((X` k) x. (Y` k))) = sum_k e. (1...N)(2 x. ((X` k) x. (Y` k)))
7136, 39, 25, 33sqrmulii 7954 . . . . . . 7 |- (sqr` (sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2))) = ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2)))
7271opreq2i 4893 . . . . . 6 |- (2 x. (sqr`
(sum_k e. (1...N)((X` k)^2) x. sum_k e. (1...N)((Y` k)^2)))) = (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2))))
7362, 70, 723brtr3i 3364 . . . . 5 |- sum_k e. (1...N)(2 x. ((X` k) x. (Y` k))) <_ (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr`
sum_k e. (1...N)((Y` k)^2))))
74 remulcl 6457 . . . . . . . . 9 |- ((2 e. RR /\ ((X` k) x. (Y` k)) e. RR) -> (2 x. ((X` k) x. (Y` k))) e. RR)
7574, 59, 9sylancr 526 . . . . . . . 8 |- (k e. (1...N) -> (2 x. ((X` k) x. (Y` k))) e. RR)
7675rgen 2159 . . . . . . 7 |- A.k e. (1...N)(2 x. ((X` k) x. (Y` k))) e. RR
77 fsumrecl 8277 . . . . . . 7 |- ((N e. (ZZ>=` 1) /\ A.k e. (1...N)(2 x. ((X` k) x. (Y` k))) e. RR) -> sum_k e. (1...N)(2 x. ((X` k) x. (Y` k))) e. RR)
783, 76, 77mp2an 761 . . . . . 6 |- sum_k e. (1...N)(2 x. ((X` k) x. (Y` k))) e. RR
7936sqrcli 7950 . . . . . . . . 9 |- (0 <_ sum_k e. (1...N)((X` k)^2) -> (sqr` sum_k e. (1...N)((X` k)^2)) e. RR)
8025, 79ax-mp 7 . . . . . . . 8 |- (sqr` sum_k e. (1...N)((X` k)^2)) e. RR
8139sqrcli 7950 . . . . . . . . 9 |- (0 <_ sum_k e. (1...N)((Y` k)^2) -> (sqr` sum_k e. (1...N)((Y` k)^2)) e. RR)
8233, 81ax-mp 7 . . . . . . . 8 |- (sqr` sum_k e. (1...N)((Y` k)^2)) e. RR
8380, 82remulcli 6488 . . . . . . 7 |- ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr`
sum_k e. (1...N)((Y` k)^2))) e. RR
8459, 83remulcli 6488 . . . . . 6 |- (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2)))) e. RR
8578, 84, 36leadd2i 6768 . . . . 5 |- (sum_k e. (1...N)(2 x. ((X` k) x. (Y` k))) <_ (2 x. ((sqr`
sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2)))) <-> (sum_k e. (1...N)((X` k)^2) + sum_k e. (1...N)(2 x. ((X` k) x. (Y` k)))) <_ (sum_k e. (1...N)((X` k)^2) + (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr`
sum_k e. (1...N)((Y` k)^2))))))
8673, 85mpbi 206 . . . 4 |- (sum_k e. (1...N)((X` k)^2) + sum_k e. (1...N)(2 x. ((X` k) x. (Y` k)))) <_ (sum_k e. (1...N)((X` k)^2) + (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr`
sum_k e. (1...N)((Y` k)^2)))))
8736, 78readdcli 6487 . . . . 5 |- (sum_k e. (1...N)((X` k)^2) + sum_k e. (1...N)(2 x. ((X` k) x. (Y` k)))) e. RR
8836, 84readdcli 6487 . . . . 5 |- (sum_k e. (1...N)((X` k)^2) + (2 x. ((sqr`
sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2))))) e. RR
8987, 88, 39leadd1i 6767 . . . 4 |- ((sum_k e. (1...N)((X` k)^2) + sum_k e. (1...N)(2 x. ((X` k) x. (Y` k)))) <_ (sum_k e. (1...N)((X` k)^2) + (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2))))) <-> ((sum_k e. (1...N)((X` k)^2) + sum_k e. (1...N)(2 x. ((X` k) x. (Y` k)))) + sum_k e. (1...N)((Y` k)^2)) <_ ((sum_k e. (1...N)((X` k)^2) + (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2))))) + sum_k e. (1...N)((Y` k)^2)))
9086, 89mpbi 206 . . 3 |- ((sum_k e. (1...N)((X` k)^2) + sum_k e. (1...N)(2 x. ((X` k) x. (Y` k)))) + sum_k e. (1...N)((Y` k)^2)) <_ ((sum_k e. (1...N)((X` k)^2) + (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2))))) + sum_k e. (1...N)((Y` k)^2))
91 reexpcl 7823 . . . . . . . . 9 |- ((((X` k) + (Y` k)) e. RR /\ 2 e. NN0) -> (((X` k) + (Y` k))^2) e. RR)
92 readdcl 6455 . . . . . . . . . 10 |- (((X` k) e. RR /\ (Y` k) e. RR) -> ((X` k) + (Y` k)) e. RR)
935, 7, 92syl11anc 524 . . . . . . . . 9 |- (k e. (1...N) -> ((X` k) + (Y` k)) e. RR)
9491, 93, 18sylancl 525 . . . . . . . 8 |- (k e. (1...N) -> (((X` k) + (Y` k))^2) e. RR)
95 sqge0 7878 . . . . . . . . 9 |- (((X` k) + (Y` k)) e. RR -> 0 <_ (((X` k) + (Y` k))^2))
9693, 95syl 12 . . . . . . . 8 |- (k e. (1...N) -> 0 <_ (((X` k) + (Y` k))^2))
9794, 96jca 310 . . . . . . 7 |- (k e. (1...N) -> ((((X` k) + (Y` k))^2) e. RR /\ 0 <_ (((X` k) + (Y` k))^2)))
9897rgen 2159 . . . . . 6 |- A.k e. (1...N)((((X` k) + (Y` k))^2) e. RR /\ 0 <_ (((X` k) + (Y` k))^2))
99 fsumcmp0 8301 . . . . . 6 |- ((N e. (ZZ>=` 1) /\ A.k e. (1...N)((((X` k) + (Y` k))^2) e. RR /\ 0 <_ (((X` k) + (Y` k))^2))) -> 0 <_ sum_k e. (1...N)(((X` k) + (Y` k))^2))
1003, 98, 99mp2an 761 . . . . 5 |- 0 <_ sum_k e. (1...N)(((X` k) + (Y` k))^2)
10194rgen 2159 . . . . . . 7 |- A.k e. (1...N)(((X` k) + (Y` k))^2) e. RR
102 fsumrecl 8277 . . . . . . 7 |- ((N e. (ZZ>=` 1) /\ A.k e. (1...N)(((X` k) + (Y` k))^2) e. RR) -> sum_k e. (1...N)(((X` k) + (Y` k))^2) e. RR)
1033, 101, 102mp2an 761 . . . . . 6 |- sum_k e. (1...N)(((X` k) + (Y` k))^2) e. RR
104103sqsqri 7971 . . . . 5 |- (0 <_ sum_k e. (1...N)(((X` k) + (Y` k))^2) -> ((sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2))^2) = sum_k e. (1...N)(((X` k) + (Y` k))^2))
105100, 104ax-mp 7 . . . 4 |- ((sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2))^2) = sum_k e. (1...N)(((X` k) + (Y` k))^2)
106 binom2 7896 . . . . . 6 |- (((X` k) e. CC /\ (Y` k) e. CC) -> (((X` k) + (Y` k))^2) = ((((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) + ((Y` k)^2)))
10764, 65, 106syl11anc 524 . . . . 5 |- (k e. (1...N) -> (((X` k) + (Y` k))^2) = ((((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) + ((Y` k)^2)))
108107sumeq2i 8248 . . . 4 |- sum_k e. (1...N)(((X` k) + (Y` k))^2) = sum_k e. (1...N)((((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) + ((Y` k)^2))
10919recnd 6468 . . . . . . . . 9 |- (k e. (1...N) -> ((X` k)^2) e. CC)
110 mulcl 6456 . . . . . . . . . 10 |- ((2 e. CC /\ ((X` k) x. (Y` k)) e. CC) -> (2 x. ((X` k) x. (Y` k))) e. CC)
111110, 63, 67sylancr 526 . . . . . . . . 9 |- (k e. (1...N) -> (2 x. ((X` k) x. (Y` k))) e. CC)
112 addcl 6454 . . . . . . . . 9 |- ((((X` k)^2) e. CC /\ (2 x. ((X` k) x. (Y` k))) e. CC) -> (((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) e. CC)
113109, 111, 112syl11anc 524 . . . . . . . 8 |- (k e. (1...N) -> (((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) e. CC)
11427recnd 6468 . . . . . . . 8 |- (k e. (1...N) -> ((Y` k)^2) e. CC)
115113, 114jca 310 . . . . . . 7 |- (k e. (1...N) -> ((((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) e. CC /\ ((Y` k)^2) e. CC))
116115rgen 2159 . . . . . 6 |- A.k e. (1...N)((((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) e. CC /\ ((Y` k)^2) e. CC)
117 fsumadd 8282 . . . . . 6 |- ((N e. (ZZ>=` 1) /\ A.k e. (1...N)((((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) e. CC /\ ((Y` k)^2) e. CC)) -> sum_k e. (1...N)((((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) + ((Y` k)^2)) = (sum_k e. (1...N)(((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) + sum_k e. (1...N)((Y` k)^2)))
1183, 116, 117mp2an 761 . . . . 5 |- sum_k e. (1...N)((((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) + ((Y` k)^2)) = (sum_k e. (1...N)(((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) + sum_k e. (1...N)((Y` k)^2))
119109, 111jca 310 . . . . . . . 8 |- (k e. (1...N) -> (((X` k)^2) e. CC /\ (2 x. ((X` k) x. (Y` k))) e. CC))
120119rgen 2159 . . . . . . 7 |- A.k e. (1...N)(((X` k)^2) e. CC /\ (2 x. ((X` k) x. (Y` k))) e. CC)
121 fsumadd 8282 . . . . . . 7 |- ((N e. (ZZ>=` 1) /\ A.k e. (1...N)(((X` k)^2) e. CC /\ (2 x. ((X` k) x. (Y` k))) e. CC)) -> sum_k e. (1...N)(((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) = (sum_k e. (1...N)((X` k)^2) + sum_k e. (1...N)(2 x. ((X` k) x. (Y` k)))))
1223, 120, 121mp2an 761 . . . . . 6 |- sum_k e. (1...N)(((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) = (sum_k e. (1...N)((X` k)^2) + sum_k e. (1...N)(2 x. ((X` k) x. (Y` k))))
123122opreq1i 4892 . . . . 5 |- (sum_k e. (1...N)(((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) + sum_k e. (1...N)((Y` k)^2)) = ((sum_k e. (1...N)((X` k)^2) + sum_k e. (1...N)(2 x. ((X` k) x. (Y` k)))) + sum_k e. (1...N)((Y` k)^2))
124118, 123eqtri 1908 . . . 4 |- sum_k e. (1...N)((((X` k)^2) + (2 x. ((X` k) x. (Y` k)))) + ((Y` k)^2)) = ((sum_k e. (1...N)((X` k)^2) + sum_k e. (1...N)(2 x. ((X` k) x. (Y` k)))) + sum_k e. (1...N)((Y` k)^2))
125105, 108, 1243eqtri 1912 . . 3 |- ((sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2))^2) = ((sum_k e. (1...N)((X` k)^2) + sum_k e. (1...N)(2 x. ((X` k) x. (Y` k)))) + sum_k e. (1...N)((Y` k)^2))
12680recni 6467 . . . . 5 |- (sqr` sum_k e. (1...N)((X` k)^2)) e. CC
12782recni 6467 . . . . 5 |- (sqr` sum_k e. (1...N)((Y` k)^2)) e. CC
128126, 127binom2i 7890 . . . 4 |- (((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr` sum_k e. (1...N)((Y` k)^2)))^2) = ((((sqr` sum_k e. (1...N)((X` k)^2))^2) + (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2))))) + ((sqr` sum_k e. (1...N)((Y` k)^2))^2))
12936sqsqri 7971 . . . . . . 7 |- (0 <_ sum_k e. (1...N)((X` k)^2) -> ((sqr` sum_k e. (1...N)((X` k)^2))^2) = sum_k e. (1...N)((X` k)^2))
13025, 129ax-mp 7 . . . . . 6 |- ((sqr` sum_k e. (1...N)((X` k)^2))^2) = sum_k e. (1...N)((X` k)^2)
131130opreq1i 4892 . . . . 5 |- (((sqr` sum_k e. (1...N)((X` k)^2))^2) + (2 x. ((sqr`
sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2))))) = (sum_k e. (1...N)((X` k)^2) + (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr`
sum_k e. (1...N)((Y` k)^2)))))
13239sqsqri 7971 . . . . . 6 |- (0 <_ sum_k e. (1...N)((Y` k)^2) -> ((sqr` sum_k e. (1...N)((Y` k)^2))^2) = sum_k e. (1...N)((Y` k)^2))
13333, 132ax-mp 7 . . . . 5 |- ((sqr` sum_k e. (1...N)((Y` k)^2))^2) = sum_k e. (1...N)((Y` k)^2)
134131, 133opreq12i 4894 . . . 4 |- ((((sqr`
sum_k e. (1...N)((X` k)^2))^2) + (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2))))) + ((sqr` sum_k e. (1...N)((Y` k)^2))^2)) = ((sum_k e. (1...N)((X` k)^2) + (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2))))) + sum_k e. (1...N)((Y` k)^2))
135128, 134eqtri 1908 . . 3 |- (((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr` sum_k e. (1...N)((Y` k)^2)))^2) = ((sum_k e. (1...N)((X` k)^2) + (2 x. ((sqr` sum_k e. (1...N)((X` k)^2)) x. (sqr` sum_k e. (1...N)((Y` k)^2))))) + sum_k e. (1...N)((Y` k)^2))
13690, 125, 1353brtr4i 3365 . 2 |- ((sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2))^2) <_ (((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr` sum_k e. (1...N)((Y` k)^2)))^2)
137103sqrge0i 7952 . . . 4 |- (0 <_ sum_k e. (1...N)(((X` k) + (Y` k))^2) -> 0 <_ (sqr`
sum_k e. (1...N)(((X` k) + (Y` k))^2)))
138100, 137ax-mp 7 . . 3 |- 0 <_ (sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2))
13936sqrge0i 7952 . . . . 5 |- (0 <_ sum_k e. (1...N)((X` k)^2) -> 0 <_ (sqr`
sum_k e. (1...N)((X` k)^2)))
14025, 139ax-mp 7 . . . 4 |- 0 <_ (sqr` sum_k e. (1...N)((X` k)^2))
14139sqrge0i 7952 . . . . 5 |- (0 <_ sum_k e. (1...N)((Y` k)^2) -> 0 <_ (sqr`
sum_k e. (1...N)((Y` k)^2)))
14233, 141ax-mp 7 . . . 4 |- 0 <_ (sqr` sum_k e. (1...N)((Y` k)^2))
14380, 82addge0i 6777 . . . 4 |- ((0 <_ (sqr` sum_k e. (1...N)((X` k)^2)) /\ 0 <_ (sqr`
sum_k e. (1...N)((Y` k)^2))) -> 0 <_ ((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr`
sum_k e. (1...N)((Y` k)^2))))
144140, 142, 143mp2an 761 . . 3 |- 0 <_ ((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr` sum_k e. (1...N)((Y` k)^2)))
145103sqrcli 7950 . . . . 5 |- (0 <_ sum_k e. (1...N)(((X` k) + (Y` k))^2) -> (sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2)) e. RR)
146100, 145ax-mp 7 . . . 4 |- (sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2)) e. RR
14780, 82readdcli 6487 . . . 4 |- ((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr`
sum_k e. (1...N)((Y` k)^2))) e. RR
148146, 147le2sqi 7870 . . 3 |- ((0 <_ (sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2)) /\ 0 <_ ((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr` sum_k e. (1...N)((Y` k)^2)))) -> ((sqr`
sum_k e. (1...N)(((X` k) + (Y` k))^2)) <_ ((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr` sum_k e. (1...N)((Y` k)^2))) <-> ((sqr`
sum_k e. (1...N)(((X` k) + (Y` k))^2))^2) <_ (((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr` sum_k e. (1...N)((Y` k)^2)))^2)))
149138, 144, 148mp2an 761 . 2 |- ((sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2)) <_ ((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr` sum_k e. (1...N)((Y` k)^2))) <-> ((sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2))^2) <_ (((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr` sum_k e. (1...N)((Y` k)^2)))^2))
150136, 149mpbir 207 1 |- (sqr` sum_k e. (1...N)(((X` k) + (Y` k))^2)) <_ ((sqr` sum_k e. (1...N)((X` k)^2)) + (sqr` sum_k e. (1...N)((Y` k)^2)))
Colors of variables: wff set class
Syntax hints:   <-> wb 163   /\ wa 240   = wceq 1298   e. wcel 1300  A.wral 2105   class class class wbr 3338  -->wf 3994  ` cfv 3998  (class class class)co 4884  CCcc 6384  RRcr 6385  0cc0 6386  1c1 6387   + caddc 6389   x. cmul 6391   <_ cle 6448  NNcn 6449  NN0cn0 6450   < clt 6653  2c2 7145  ZZ>=cuz 7586  ...cfz 7637  ^cexp 7811  sqrcsqr 7919  abscabs 8000  sum_csu 8239
This theorem is referenced by:  trirn 15834
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-5 1302  ax-7 1304  ax-gen 1305  ax-8 1306  ax-9 1307  ax-10 1308  ax-11 1309  ax-12 1310  ax-13 1311  ax-14 1312  ax-17 1317  ax-4 1319  ax-5o 1321  ax-6o 1324  ax-9o 1481  ax-10o 1500  ax-16 1580  ax-11o 1588  ax-ext 1865  ax-rep 3428  ax-sep 3438  ax-nul 3445  ax-pow 3481  ax-pr 3524  ax-un 3790  ax-inf2 5731
This theorem depends on definitions:  df-bi 164  df-or 241  df-an 242  df-3or 859  df-3an 860  df-ex 1327  df-sb 1536  df-eu 1775  df-mo 1776  df-clab 1872  df-cleq 1877  df-clel 1880  df-ne 2019  df-nel 2020  df-ral 2109  df-rex 2110  df-reu 2111  df-rab 2112  df-v 2294  df-sbc 2454  df-csb 2541  df-dif 2597  df-un 2600  df-in 2603  df-ss 2605  df-pss 2607  df-nul 2876  df-if 2983  df-pw 3035  df-sn 3049  df-pr 3050  df-tp 3052  df-op 3053  df-uni 3178  df-int 3215  df-iun 3257  df-br 3339  df-opab 3396  df-tr 3412  df-eprel 3583  df-id 3586  df-po 3591  df-so 3604  df-fr 3625  df-we 3644  df-ord 3660  df-on 3661  df-lim 3662  df-suc 3663  df-om 3950  df-xp 4000  df-rel 4001  df-cnv 4002  df-co 4003  df-dm 4004  df-rn 4005  df-res 4006  df-ima 4007  df-fun 4008  df-fn 4009  df-f 4010  df-f1 4011  df-fo 4012  df-f1o 4013  df-fv 4014  df-opr 4886  df-oprab 4887  df-mpt 5006  df-1st 5020  df-2nd 5021  df-iota 5089  df-rdg 5140  df-1o 5177  df-oadd 5179  df-omul 5180  df-er 5318  df-ec 5320  df-qs 5323  df-en 5427  df-dom 5428  df-sdom 5429  df-undef 5556  df-riota 5560  df-sup 5664  df-ni 6152  df-pli 6153  df-mi 6154  df-lti 6155  df-plpq 6187  df-mpq 6188  df-enq 6189  df-nq 6190  df-plq 6191  df-mq 6192  df-rq 6193  df-ltq 6194  df-1q 6195  df-np 6238  df-1p 6239  df-plp 6240  df-mp 6241  df-ltp 6242  df-plpr 6316  df-mpr 6317  df-enr 6318  df-nr 6319  df-plr 6320  df-mr 6321  df-ltr 6322  df-0r 6323  df-1r 6324  df-m1r 6325  df-c 6392  df-0 6393  df-1 6394  df-i 6395  df-r 6396  df-plus 6397  df-mul 6398  df-lt 6399  df-sub 6511  df-neg 6513  df-pnf 6654  df-mnf 6655  df-xr 6656  df-ltxr 6657  df-le 6658  df-div 6892  df-n 7108  df-2 7154  df-3 7155  df-4 7156  df-n0 7309  df-z 7345  df-uz 7587  df-fz 7638  df-seq1 7721  df-shft 7754  df-seqz 7776  df-exp 7812  df-sqr 7920  df-re 8001  df-im 8002  df-cj 8003  df-abs 8004  df-sum 8240
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