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Theorem njtlc 14389
Description: An injection is left-cancelable.
Assertion
Ref Expression
njtlc |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> ((F o. H) = (F o. K) -> H = K))

Proof of Theorem njtlc
StepHypRef Expression
1 f1f 4610 . . . . . . . . . 10 |- (F:B-1-1->C -> F:B-->C)
2 ffun 4565 . . . . . . . . . 10 |- (F:B-->C -> Fun F)
31, 2syl 12 . . . . . . . . 9 |- (F:B-1-1->C -> Fun F)
433ad2ant1 897 . . . . . . . 8 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> Fun F)
54adantr 425 . . . . . . 7 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> Fun F)
6 simpl2 880 . . . . . . 7 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> H:A-->B)
7 simpr 350 . . . . . . 7 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> x e. A)
8 fvco3 4739 . . . . . . 7 |- ((Fun F /\ H:A-->B /\ x e. A) -> ((F o. H)` x) = (F` (H` x)))
95, 6, 7, 8syl111anc 1100 . . . . . 6 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> ((F o. H)` x) = (F` (H` x)))
10 simpl3 881 . . . . . . 7 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> K:A-->B)
11 fvco3 4739 . . . . . . 7 |- ((Fun F /\ K:A-->B /\ x e. A) -> ((F o. K)` x) = (F` (K` x)))
125, 10, 7, 11syl111anc 1100 . . . . . 6 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> ((F o. K)` x) = (F` (K` x)))
139, 12eqeq12d 1899 . . . . 5 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> (((F o. H)` x) = ((F o. K)` x) <-> (F` (H` x)) = (F` (K` x))))
14 simpl1 879 . . . . . 6 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> F:B-1-1->C)
15 ffvelrn 4787 . . . . . . 7 |- ((H:A-->B /\ x e. A) -> (H` x) e. B)
16153ad2antl2 1039 . . . . . 6 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> (H` x) e. B)
17 ffvelrn 4787 . . . . . . 7 |- ((K:A-->B /\ x e. A) -> (K` x) e. B)
18173ad2antl3 1040 . . . . . 6 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> (K` x) e. B)
19 f1fveq 4852 . . . . . . 7 |- ((F:B-1-1->C /\ ((H` x) e. B /\ (K` x) e. B)) -> ((F` (H` x)) = (F` (K` x)) <-> (H` x) = (K` x)))
2019biimpd 170 . . . . . 6 |- ((F:B-1-1->C /\ ((H` x) e. B /\ (K` x) e. B)) -> ((F` (H` x)) = (F` (K` x)) -> (H` x) = (K` x)))
2114, 16, 18, 20syl12anc 1098 . . . . 5 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> ((F` (H` x)) = (F` (K` x)) -> (H` x) = (K` x)))
2213, 21sylbid 220 . . . 4 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> (((F o. H)` x) = ((F o. K)` x) -> (H` x) = (K` x)))
2322ralimdvaa 2171 . . 3 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> (A.x e. A ((F o. H)` x) = ((F o. K)` x) -> A.x e. A (H` x) = (K` x)))
2423anim2d 620 . 2 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> ((A = A /\ A.x e. A ((F o. H)` x) = ((F o. K)` x)) -> (A = A /\ A.x e. A (H` x) = (K` x))))
25 ffn 4562 . . . . . 6 |- (F:B-->C -> F Fn B)
26 fnfco 4581 . . . . . . 7 |- ((F Fn B /\ H:A-->B) -> (F o. H) Fn A)
2726ex 402 . . . . . 6 |- (F Fn B -> (H:A-->B -> (F o. H) Fn A))
281, 25, 273syl 24 . . . . 5 |- (F:B-1-1->C -> (H:A-->B -> (F o. H) Fn A))
2928imp 377 . . . 4 |- ((F:B-1-1->C /\ H:A-->B) -> (F o. H) Fn A)
30293adant3 896 . . 3 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> (F o. H) Fn A)
31 fnfco 4581 . . . . . . 7 |- ((F Fn B /\ K:A-->B) -> (F o. K) Fn A)
3231ex 402 . . . . . 6 |- (F Fn B -> (K:A-->B -> (F o. K) Fn A))
331, 25, 323syl 24 . . . . 5 |- (F:B-1-1->C -> (K:A-->B -> (F o. K) Fn A))
3433imp 377 . . . 4 |- ((F:B-1-1->C /\ K:A-->B) -> (F o. K) Fn A)
35343adant2 895 . . 3 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> (F o. K) Fn A)
36 eqfnfv 4766 . . 3 |- (((F o. H) Fn A /\ (F o. K) Fn A) -> ((F o. H) = (F o. K) <-> (A = A /\ A.x e. A ((F o. H)` x) = ((F o. K)` x))))
3730, 35, 36syl11anc 524 . 2 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> ((F o. H) = (F o. K) <-> (A = A /\ A.x e. A ((F o. H)` x) = ((F o. K)` x))))
38 ffn 4562 . . . . 5 |- (H:A-->B -> H Fn A)
39 ffn 4562 . . . . 5 |- (K:A-->B -> K Fn A)
4038, 39anim12i 360 . . . 4 |- ((H:A-->B /\ K:A-->B) -> (H Fn A /\ K Fn A))
41403adant1 894 . . 3 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> (H Fn A /\ K Fn A))
42 eqfnfv 4766 . . 3 |- ((H Fn A /\ K Fn A) -> (H = K <-> (A = A /\ A.x e. A (H` x) = (K` x))))
4341, 42syl 12 . 2 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> (H = K <-> (A = A /\ A.x e. A (H` x) = (K` x))))
4424, 37, 433imtr4d 602 1 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> ((F o. H) = (F o. K) -> H = K))
Colors of variables: wff set class
Syntax hints:   -> wi 3   <-> wb 163   /\ wa 240   /\ w3a 858   = wceq 1298   e. wcel 1300  A.wral 2105   o. ccom 3990  Fun wfun 3992   Fn wfn 3993  -->wf 3994  -1-1->wf1 3995  ` cfv 3998
This theorem is referenced by:  injsurinj 14487
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  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-sep 3438  ax-nul 3445  ax-pow 3481  ax-pr 3524  ax-un 3790
This theorem depends on definitions:  df-bi 164  df-or 241  df-an 242  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-ral 2109  df-rex 2110  df-v 2294  df-dif 2597  df-un 2600  df-in 2603  df-ss 2605  df-nul 2876  df-pw 3035  df-sn 3049  df-pr 3050  df-op 3053  df-uni 3178  df-br 3339  df-opab 3396  df-id 3586  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-fv 4014
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