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Theorem njtlc 15360
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 4736 . . . . . . . . . 10 |- (F:B-1-1->C -> F:B-->C)
2 ffun 4700 . . . . . . . . . 10 |- (F:B-->C -> Fun F)
31, 2syl 13 . . . . . . . . 9 |- (F:B-1-1->C -> Fun F)
433ad2ant1 1169 . . . . . . . 8 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> Fun F)
54adantr 543 . . . . . . 7 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> Fun F)
6 simpl2 1152 . . . . . . 7 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> H:A-->B)
7 simpr 538 . . . . . . 7 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> x e. A)
8 fvco3 4863 . . . . . . 7 |- ((Fun F /\ H:A-->B /\ x e. A) -> ((F o. H)` x) = (F` (H` x)))
95, 6, 7, 8syl111anc 1377 . . . . . 6 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> ((F o. H)` x) = (F` (H` x)))
10 simpl3 1153 . . . . . . 7 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> K:A-->B)
11 fvco3 4863 . . . . . . 7 |- ((Fun F /\ K:A-->B /\ x e. A) -> ((F o. K)` x) = (F` (K` x)))
125, 10, 7, 11syl111anc 1377 . . . . . 6 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> ((F o. K)` x) = (F` (K` x)))
139, 12eqeq12d 2184 . . . . 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 1151 . . . . . 6 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> F:B-1-1->C)
15 ffvelrn 4916 . . . . . . 7 |- ((H:A-->B /\ x e. A) -> (H` x) e. B)
16153ad2antl2 1317 . . . . . 6 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> (H` x) e. B)
17 ffvelrn 4916 . . . . . . 7 |- ((K:A-->B /\ x e. A) -> (K` x) e. B)
18173ad2antl3 1318 . . . . . 6 |- (((F:B-1-1->C /\ H:A-->B /\ K:A-->B) /\ x e. A) -> (K` x) e. B)
19 f1fveq 4986 . . . . . . 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 244 . . . . . 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 1375 . . . . 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 267 . . . 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)))
2322ralimdva 2451 . . 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 631 . 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 4698 . . . . . 6 |- (F:B-->C -> F Fn B)
26 fnfco 4713 . . . . . . 7 |- ((F Fn B /\ H:A-->B) -> (F o. H) Fn A)
2726ex 494 . . . . . 6 |- (F Fn B -> (H:A-->B -> (F o. H) Fn A))
281, 25, 273syl 38 . . . . 5 |- (F:B-1-1->C -> (H:A-->B -> (F o. H) Fn A))
2928imp 489 . . . 4 |- ((F:B-1-1->C /\ H:A-->B) -> (F o. H) Fn A)
30293adant3 1168 . . 3 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> (F o. H) Fn A)
31 fnfco 4713 . . . . . . 7 |- ((F Fn B /\ K:A-->B) -> (F o. K) Fn A)
3231ex 494 . . . . . 6 |- (F Fn B -> (K:A-->B -> (F o. K) Fn A))
331, 25, 323syl 38 . . . . 5 |- (F:B-1-1->C -> (K:A-->B -> (F o. K) Fn A))
3433imp 489 . . . 4 |- ((F:B-1-1->C /\ K:A-->B) -> (F o. K) Fn A)
35343adant2 1167 . . 3 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> (F o. K) Fn A)
36 eqfnfv 4892 . . 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 755 . 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 4698 . . . . 5 |- (H:A-->B -> H Fn A)
39 ffn 4698 . . . . 5 |- (K:A-->B -> K Fn A)
4038, 39anim12i 632 . . . 4 |- ((H:A-->B /\ K:A-->B) -> (H Fn A /\ K Fn A))
41403adant1 1166 . . 3 |- ((F:B-1-1->C /\ H:A-->B /\ K:A-->B) -> (H Fn A /\ K Fn A))
42 eqfnfv 4892 . . 3 |- ((H Fn A /\ K Fn A) -> (H = K <-> (A = A /\ A.x e. A (H` x) = (K` x))))
4341, 42syl 13 . 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 331 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 231   /\ wa 433   /\ w3a 1130   = wceq 1615   e. wcel 1617  A.wral 2385   o. ccom 4155  Fun wfun 4157   Fn wfn 4158  -->wf 4159  -1-1->wf1 4160  ` cfv 4163
This theorem is referenced by:  injsurinj 15487
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 1621  ax-gen 1622  ax-8 1623  ax-9 1624  ax-10 1625  ax-11 1626  ax-12 1627  ax-13 1628  ax-14 1629  ax-17 1634  ax-4 1637  ax-5o 1639  ax-6o 1642  ax-9o 1792  ax-10o 1810  ax-16 1883  ax-11o 1893  ax-ext 2152  ax-sep 3638  ax-nul 3645  ax-pow 3681  ax-pr 3719  ax-un 3961
This theorem depends on definitions:  df-bi 232  df-or 434  df-an 435  df-3an 1132  df-ex 1645  df-sb 1845  df-eu 2070  df-mo 2071  df-clab 2158  df-cleq 2163  df-clel 2166  df-ne 2297  df-ral 2389  df-rex 2390  df-v 2571  df-dif 2862  df-un 2864  df-in 2866  df-ss 2868  df-nul 3115  df-pw 3261  df-sn 3274  df-pr 3275  df-op 3278  df-uni 3399  df-br 3540  df-opab 3598  df-id 3779  df-xp 4165  df-rel 4166  df-cnv 4167  df-co 4168  df-dm 4169  df-rn 4170  df-res 4171  df-ima 4172  df-fun 4173  df-fn 4174  df-f 4175  df-f1 4176  df-fv 4179
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