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Theorem divadddivt 5740
Description: Addition of two ratios. Theorem I.13 of [Apostol] p. 18.
Assertion
Ref Expression
divadddivt |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> ((A / B) + (C / D)) = (((A x. D) + (B x. C)) / (B x. D)))

Proof of Theorem divadddivt
StepHypRef Expression
1 muln0bt 5666 . . . . 5 |- ((B e. CC /\ D e. CC) -> ((B =/= 0 /\ D =/= 0) <-> (B x. D) =/= 0))
21ad2ant2l 408 . . . 4 |- (((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) -> ((B =/= 0 /\ D =/= 0) <-> (B x. D) =/= 0))
3 divdirt 5713 . . . . . 6 |- ((((A x. D) e. CC /\ (B x. C) e. CC /\ (B x. D) e. CC) /\ (B x. D) =/= 0) -> (((A x. D) + (B x. C)) / (B x. D)) = (((A x. D) / (B x. D)) + ((B x. C) / (B x. D))))
43ex 373 . . . . 5 |- (((A x. D) e. CC /\ (B x. C) e. CC /\ (B x. D) e. CC) -> ((B x. D) =/= 0 -> (((A x. D) + (B x. C)) / (B x. D)) = (((A x. D) / (B x. D)) + ((B x. C) / (B x. D)))))
5 axmulcl 5245 . . . . . 6 |- ((A e. CC /\ D e. CC) -> (A x. D) e. CC)
65ad2ant2rl 411 . . . . 5 |- (((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) -> (A x. D) e. CC)
7 axmulcl 5245 . . . . . 6 |- ((B e. CC /\ C e. CC) -> (B x. C) e. CC)
87ad2ant2lr 410 . . . . 5 |- (((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) -> (B x. C) e. CC)
9 axmulcl 5245 . . . . . 6 |- ((B e. CC /\ D e. CC) -> (B x. D) e. CC)
109ad2ant2l 408 . . . . 5 |- (((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) -> (B x. D) e. CC)
114, 6, 8, 10syl3anc 856 . . . 4 |- (((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) -> ((B x. D) =/= 0 -> (((A x. D) + (B x. C)) / (B x. D)) = (((A x. D) / (B x. D)) + ((B x. C) / (B x. D)))))
122, 11sylbid 203 . . 3 |- (((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) -> ((B =/= 0 /\ D =/= 0) -> (((A x. D) + (B x. C)) / (B x. D)) = (((A x. D) / (B x. D)) + ((B x. C) / (B x. D)))))
1312imp 350 . 2 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> (((A x. D) + (B x. C)) / (B x. D)) = (((A x. D) / (B x. D)) + ((B x. C) / (B x. D))))
14 dividt 5722 . . . . . . 7 |- ((D e. CC /\ D =/= 0) -> (D / D) = 1)
1514ad2ant2l 408 . . . . . 6 |- (((C e. CC /\ D e. CC) /\ (B =/= 0 /\ D =/= 0)) -> (D / D) = 1)
1615adantll 392 . . . . 5 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> (D / D) = 1)
1716opreq2d 3961 . . . 4 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> ((A / B) x. (D / D)) = ((A / B) x. 1))
18 divmuldivt 5736 . . . . 5 |- ((((A e. CC /\ B e. CC) /\ (D e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> ((A / B) x. (D / D)) = ((A x. D) / (B x. D)))
19 pm3.27 323 . . . . . 6 |- ((C e. CC /\ D e. CC) -> D e. CC)
2019, 19jca 288 . . . . 5 |- ((C e. CC /\ D e. CC) -> (D e. CC /\ D e. CC))
2118, 20sylanl2 461 . . . 4 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> ((A / B) x. (D / D)) = ((A x. D) / (B x. D)))
22 divclt 5681 . . . . . . 7 |- ((A e. CC /\ B e. CC /\ B =/= 0) -> (A / B) e. CC)
23223expa 831 . . . . . 6 |- (((A e. CC /\ B e. CC) /\ B =/= 0) -> (A / B) e. CC)
24 ax1id 5254 . . . . . 6 |- ((A / B) e. CC -> ((A / B) x. 1) = (A / B))
2523, 24syl 10 . . . . 5 |- (((A e. CC /\ B e. CC) /\ B =/= 0) -> ((A / B) x. 1) = (A / B))
2625ad2ant2r 409 . . . 4 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> ((A / B) x. 1) = (A / B))
2717, 21, 263eqtr3d 1507 . . 3 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> ((A x. D) / (B x. D)) = (A / B))
28 dividt 5722 . . . . . . 7 |- ((B e. CC /\ B =/= 0) -> (B / B) = 1)
2928ad2ant2lr 410 . . . . . 6 |- (((A e. CC /\ B e. CC) /\ (B =/= 0 /\ D =/= 0)) -> (B / B) = 1)
3029adantlr 393 . . . . 5 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> (B / B) = 1)
3130opreq1d 3960 . . . 4 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> ((B / B) x. (C / D)) = (1 x. (C / D)))
32 divmuldivt 5736 . . . . 5 |- ((((B e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> ((B / B) x. (C / D)) = ((B x. C) / (B x. D)))
33 pm3.27 323 . . . . . 6 |- ((A e. CC /\ B e. CC) -> B e. CC)
3433, 33jca 288 . . . . 5 |- ((A e. CC /\ B e. CC) -> (B e. CC /\ B e. CC))
3532, 34sylanl1 460 . . . 4 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> ((B / B) x. (C / D)) = ((B x. C) / (B x. D)))
36 divclt 5681 . . . . . . 7 |- ((C e. CC /\ D e. CC /\ D =/= 0) -> (C / D) e. CC)
37363expa 831 . . . . . 6 |- (((C e. CC /\ D e. CC) /\ D =/= 0) -> (C / D) e. CC)
38 mulid2t 5389 . . . . . 6 |- ((C / D) e. CC -> (1 x. (C / D)) = (C / D))
3937, 38syl 10 . . . . 5 |- (((C e. CC /\ D e. CC) /\ D =/= 0) -> (1 x. (C / D)) = (C / D))
4039ad2ant2l 408 . . . 4 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> (1 x. (C / D)) = (C / D))
4131, 35, 403eqtr3d 1507 . . 3 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> ((B x. C) / (B x. D)) = (C / D))
4227, 41opreq12d 3963 . 2 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> (((A x. D) / (B x. D)) + ((B x. C) / (B x. D))) = ((A / B) + (C / D)))
4313, 42eqtr2d 1500 1 |- ((((A e. CC /\ B e. CC) /\ (C e. CC /\ D e. CC)) /\ (B =/= 0 /\ D =/= 0)) -> ((A / B) + (C / D)) = (((A x. D) + (B x. C)) / (B x. D)))
Colors of variables: wff set class
Syntax hints:   -> wi 3   <-> wb 146   /\ wa 223   /\ w3a 773   = wceq 953   e. wcel 955   =/= wne 1577  (class class class)co 3948  CCcc 5204  0cc0 5206  1c1 5207   + caddc 5209   x. cmul 5211   / cdiv 5266
This theorem is referenced by:  divadddiv 5744  qaddclt 6207
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